Godzilla vs. Gamera: Earth Defense Directive

Godzilla vs. Gamera: Earth Defense Directive is an upcoming fighting game co-developed by Creative Assembly and Toho Studios and published by Sega for the PlayStation 5, Xbox Series X/S, and Nintendo Switch. The game is a crossover between Toho's Godzilla franchise and Kadowaka Daiei Studio's Gamera franchise, featuring giant monsters from both film series in the first major multi-franchise crossover between both properties. It is set to be released on November 27, 2025, the 60th anniversary of the Gamera franchise.

The game features similar gameplay to the Godzilla fighting game trilogy developed by Pipeworks Software, Inc., and much of its main plot is derivative of that of Godzilla: Unleashed. Other than that, it is a largely original game and features a completely different backstory, functioning as more of a spiritual successor to the Pipeworks trilogy. The storyline, set in the near-future, involves the United Nations Global Defense Initiative faced with an interstellar war between two alien races that makes its way to Earth. The conflict results in a global outbreak of mysterious crystal formations, which cause natural disasters and anomalies that threaten the entire planet. The situation is further complicated as the crystals agitate Earth's Titan and mutant monsters, leading to several conflicts.

Godzilla vs. Gamera is famous for featuring nearly every monster in both the Godzilla and Gamera series, and features nods and shout-outs to films and lore elements affiliated with the two franchises.

Story
Godzilla vs. Gamera is not set in any particular film continuity, and comprises a largely original fictional universe that is a amalgamation of elements from all across the Godzilla and Gamera film franchises. According to in-game backstory, a battle between Godzilla and Gamera took place in San Francisco in 2024 that resulted in over 50,000 civilian deaths. In response to the catastrophe, the United Nations banded together to form the Global Defense Initiative (GDI), a mutual defense pact dedicated to safeguarding mankind from giant monsters. Over the next decades, the GDI issues a campaign to subdue Earth's monsters. Standing at the forefront of their operation is the "mechas", giant, human-operated robots which become the vangaurds of their military arm. The GDI proves to be highly successful, and within thirty years, all of Earth's monsters have been rounded up and collected at Monster Island, an advanced scientific research and containment installation situated in the Bonin Islands.

The game's main events take place in the year 2054, by which time there has been little monster activity in years. The peace is disrupted when an unexpected meteor shower hits Earth, and soon after, a technologically advanced alien race called the Mysterians make first contact with humanity by deploying their M.O.G.U.E.R.A. robots to attack major cities. After a mutual misunderstanding, the GDI realizes the Mysterians are not targeting the cities, but rather large crystal formations that have begun sprouting from the meteor impact zones. Meanwhile, the crystals damage the containment facilities at Monster Island, letting all of the monsters loose upon the world. They begin attacking major cities, drawn to the energies given off by the crystals. Further worsening the situation is the appearance of a second alien race called the Viras, who seek to harness the crystals to benefit their ongoing war with the Mysterians, and have gathered their own army of monsters to do so.

Four factions are formed as a result of the crisis: the Titans, comprising Earth's natural monsters; the GDI itself, which includes both its robots and the forces of the Mysterians who have allied with them; the Aliens, which includes all of the alien monsters under the control of the Viras; and the Mutants, which includes Earth monsters created through unnatural means that have no true alignment.

Playable Characters
The game features over forty different monsters and robots from the Godzilla and Gamera franchises. To better fit in with the fictional setting in the game, many of the monsters have reworked origin stories.

Titans
"Titan" is a term originating from the MonsterVerse that is used in the game by the Global Defense Initiative to describe kaiju that were born naturally on Earth. Titans are driven by the instinctual desire to protect their environment, and by extension the planet as whole. Thus, they will go out of their way to target hostile alien and mutant monsters that threaten the planet, as well as any harmful, human-engineered machines. Monsters affiliated with this faction generally don't care much for humans and will not hesitate to destroy human cities to accomplish their goals.
 * Anguirus - An enormous spiked reptile vaguely resembling an ankylosaurid, Anguirus is one of the three guardians of Yamato, a trio of ancient beasts that were charged with safeguarding the world in the distant past. They were previously awakened in 2001 to combat the threat of their ancient nemesis, Bagan, and have been awakened once more in response to the crystal outbreak. His appearance in the game is based on an unused design for the cancelled film, Godzilla X Varan, Baragon and Anguirus: Giant Monsters All-Out Attack, and also has ice-based powers not seen in any of his film incarnations.
 * Baragon - While resembling an enormous reptile or non-mammalian synapsid, Baragon is actually one of the guardians of Yamato alongside Anguirus and Varan. Prior to the crystal outbreak, Baragon was active on two separate occasions in the past. The first was in 1965, when he woke to combat a giant version of Frankenstein's monster; and the second was in 2001 to battle Bagan. His appearance is based on his design from 2001's Godzilla, Mothra and King Ghidorah: Giant Monsters All-Out Attack.
 * Behemoth - The Behemoth is a tusked, sloth-like creature that, like Godzilla and Rodan, is a survivor of prehistoric times. It is unusually friendly compared to most other Titans, having never displayed any hostility towards humanity in the past. However, it will not hesitate to act in self-defense of itself and the Earth.
 * Ebirah - An enormous lobster that was once used as a biological weapon by the Red Bamboo, a Japanese terrorist organization that was active throughout the 1960s and early 1970s. After being defeated in battle by King Kong, Ebirah vanished for a length of time before being captured by the GDI and placed on Monster Island. Ebirah's origins are unclear, though it is theorized that it is another prehistoric superspecies that survived into the modern day.
 * Gamera - A titanic turtle-like beast with the ability to breathe fire and fly using organic rocket jets in his shell. Unlike most Titans, Gamera is not a natural creature, but rather a bioengineered super-being. Roughly 8,000 years ago, he was created by a long-lost alien race known as the Kilaaks, who had settled on Earth and established a civilization that inspired the legend of Atlantis. He was created originally to fight the rampant Gyaos, and continues to protect the Earth from other threats. Gamera has a strong empathy towards humanity and goes out of his way to protect them. However, after his destructive battle against Godzilla in 2024, much of mankind looks upon him with scorn. He has not been seen since, and it is only after the crystal outbreak that he makes his return. His design is based on his appearance in the 1996 film, Gamera 2: Advent of Legion.
 * Godzilla - Undoubtedly one of the most powerful monsters on Earth, Godzilla is the unchallenged 'King of the Monsters' who functions as an alpha amongst the other Titans. An enormous reptilian beast from the Permian period, Godzilla survived the multiple extinction events by feeding off of geothermal radiation beneath the planet's crust. He first surfaced in 1954 after being provoked by the Castle Bravo nuclear tests, and has continued to menace mankind over the decades. Despite his cold history with humanity, he has saved the planet from worse threats many times. After a horrific battle between him and Gamera in 2024 nearly wiped out the city of San Francisco, Godzilla was fought many times by the GDI before finally being subdued and imprisoned at Monster Island by Mechagodzilla II. He has been freed since the crystal outbreak, and seeks to end it while holding an intense grudge towards humanity.
 * Three versions of Godzilla are playable in the game, each based on a different iteration from. Each of these versions has their own powers and movesets: the Godzilla from 1962's King Kong vs. Godzilla; one based on his appearance in the Heisei period; and the MonsterVerse incarnation.
 * Gorosaurus - An ancient reptile resembling an allosaur, Gorosaurus is another prehistoric endling. Throughout history, there have been four living individuals encountered by humans. Three were first encountered on Skull Island during the 1973 expedition to the island, and a fourth appeared in 1983 where it was killed in battle by Titanosaurus in Osaka. Two of the Skull Island Gorosauruses were killed by King Kong at some point, and after the island was destroyed in a cataclysm, many of its native creatures, including the last Gorosaurus, were moved from there to Monster Island.
 * King Caesar - King Caesar is a mysterious, lion/stone golem-like creature that serves as a benevolent guardian of the Azumis, an aristocratic family living on the island of Okinawa in the Kyushu archipelago of Japan. Although he was instrumental in helping defeat King Ghidorah in 1991, the GDI has built a containment facility around the shrine at Okinawa where he sleeps. After the crystal outbreak, the Azumi family have awakened him to help the Titans in dealing with the crisis. His design in the game is based on his appearance in Godzilla: Final Wars, but with the abilities of his Showa incarnation.
 * King Kong - King Kong, the Eighth Wonder of the World, is a titanic ape originating from Skull Island, an island in the Pacific Ocean that has since been annihilated by a natural disaster. He was first discovered in 1933 as a juvenile by a documentary film crew, and in 1973, a scientific expedition to the island transported him to civilization. This incident led to a disastrous rampage that culminated in a battle between Kong and Godzilla at Mt. Fuji. The fight ended in a draw, and Kong was safely transported back to Skull Island. Since the island's destruction, Kong has been safely relocated to Monster Island. Kong's appearance in the game is based on his MonsterVerse incarnation.
 * Mothra - Mothra is a mystical, moth-like being from Infant Island, a landmass in the South Pacific where she lords over a primitive human culture. Her origins are hard to decipher, but it is generally believed that she is a literal goddess in living form. She made first contact with humanity in 1961 after she attacked Tokyo, but later came to the nation's defense against Godzilla three years later. Since then, Mothra has come to mankind's aid against other monsters, and by present day, is one of the few Titans that is actually a full ally to the GDI and has not been contained on Monster Island.
 * Two versions of Mothra are playable in the game, each with different movesets. One is based on her appearance in 2003's Godzilla: Tokyo S.O.S., but with the powers of her Heisei incarnation; and the other is based on her incarnation from the MonsterVerse.
 * Rodan - A pterosaur-like beast, Rodan is, like Godzilla, a prehistoric superspecies from the Permian that survived by living off of geothermal radiation. Two Rodans, a male and a female, hatched from eggs that laid dormant deep underground on the island of Isla de Maro near Mexico. Kept alive by radiation deposits in the surrounding soil, the eggs were eventually unearthed in 1956 by miners and subsequently hatched. After rampaging through Mexico, the two Rodans were eventually killed by a military operation, but decades later, a third Rodan, possibly an offspring of the original two, appeared from the same island. It fought both Godzilla and King Ghidorah during the latter's rampage in 1991 before hibernating at the volcano at Isla de Maro. After the founding of the GDI, Rodan was subdued by Mechagodzilla and contained at Monster Island.
 * Two versions of Rodan are playable in the game, each with their own powers and movesets. One is based on his Heisei incarnation, while the other is based on his incarnation from the MonsterVerse.
 * Titanosaurus - Another ancient aquatic reptile similar to Godzilla, Titanosaurus is a seafaring creature similar in appearance to a Spinosaurus with the ability to fire a wave of supersonic energy from its mouth. First discovered in the 1960s, Titanosaurus was the object of study to a scientist named Akira Ichinose, but in 1983, it engaged a member of Gorosaurus' kind in a battle that wrecked most of Osaka. After that, it returned to the city, and was later corralled to Monster Island by the GDI.
 * Varan - One of the three guardians of Yamato, Varan is a reptilian creature resembling a sort of lizard with a gliding, skin-like membrane similar to that of flying squirrels. Unlike its counterparts, Anguirus and Baragon, Varan shows complete amity towards humans. This is because its resting place, a lake in the Japanese countryside, is also the location of a peaceful fishing community, whose residents tend to Varan. After helping stop Bagan in 2001, Varan has not shown any hostility towards mankind, and came to its defense almost immediately during the crystal outbreak.

GDI
The Global Defense Initiative (GDI) is a scientific paramilitary organization formed in 2024 by the United Nations to protect the Earth from monster activity. It is based on the Earth Defense Force, a similar organization that featured heavily in the 2004 film Godzilla: Final Wars. A milestone of their agency is their mechas, giant robots that vary from being human-operated, remote controlled, or artificially intelligent, and were hugely successful in neutralizing Earth's monsters prior to the events of the game. During the crystal outbreak, the GDI forms an alliance with the Mysterians (the alien race that first appeared in the 1957 film The Mysterians), who integrate their own military forces and mechas into their ranks. The two factions are united against the Viras and any hostile monsters that seek to use the crystals for malicious purposes, but will also work to defend cities from the Titans should any of them prove hostile.
 * Jet Jaguar - A humanoid robot with an artificial intelligence and the ability to alter its own size. Based on the mascot of the same name of the multinational technology supplier Apex Cybernetics, Jet Jaguar was created to represent the company during a technological arms race influenced by the GDI's rise to power. Apex eventually went bankrupt after the disastrous test run of its prototype Mechagodzilla, and its assets were acquired by the GDI in a fiercely contested hostile takeover. Jet Jaguar fell into the possession of one of the GDI's amateur roboticists, Goro Ibuki. Under Ibuki's care, Jet Jaguar's AI was improved and it began upgrading itself extensively without Ibuki's immediate knowledge. During an attack by Godzilla in 2033, Jet Jaguar came to humanity's defense when the attack endangered Ibuki, and while it was heavily damaged, it succeeded in driving Godzilla away from the city. Jet Jaguar was subsequently added to the GDI's lineup of mechas.
 * Kiryu - The latest in the GDI's mecha lineup, Kiryu, sometimes referred to as Mechagodzilla III, was created in 2052 as a potential replacement for Mechagodzilla II. Unlike the fully autonomous Mechagodzilla II, Kiryu is a biomechanoid built around the skeleton of another member of Godzilla's kind, which was found in the Philippines. It is guided by combination of both remote systems and a virtual intelligence powered by bioelectric signals given off by the skeleton's spinal cord. While more geared towards physical combat, Kiryu is equipped with a powerful arsenal of advanced weaponry, including an electric maser cannon, guided missile launchers, and a devastating absolute zero cannon. The crystal outbreak saw Kiryu's first deployment on the field, and the GDI is uncertain of whether it'll be effective or not against this global threat.
 * Mecha-King Ghidorah - The third addition to the GDI's mecha lineup, Mecha-King Ghidorah was the GDI's first successful attempt at a cybernetic war machine. It is the result of the GDI fusing technology with the original King Ghidorah that was killed by Godzilla in 1991, and has all of the original Ghidorah's abilities, plus a few added weapons like a laser beam, heat-seeking taser, and a force field generator. Unlike many mechas in the GDI's arsenal, Mecha-King Ghidorah has seen little combat, but with the rise of the crystal outbreak and the Viras invasion, veteran GDI pilot Catherine Matton has stepped up to give the cyborg a chance. Mecha-King Ghidorah's design in the game is a unique fusion between its Heisei incarnation and King Ghidorah's design for 1998's Rebirth of Mothra III.
 * Mechagodzilla II - Arguably the GDI's most powerful mecha, Mechagodzilla II is a human-engineered replica of the original Mechagodzilla that was deployed by a race of alien invaders in the 1970s, and was in fact built by reverse engineering the alien technology. It is the most physically durable of all of the GDI's mechas, and is equipped with an enormous array of energy-based weapons like laser eyes, a plasma cannon, electric shock cables, wrist lasers, and a diamond exterior that can absorb energy and convert it into a devastating plasma grenade burst. From 2040 to 2050, Mechagodzilla II was the vanguard of the GDI's campaign against Godzilla and other giant monsters, successfully defeating several including Godzilla himself in a battle in Tokyo. By 2054, it has been improved significantly, and once again stands at the forefront of the GDI as it is faced with the threat of the aliens and the crystals.
 * Mechani-Kong - A combat mech created to resemble King Kong, Mechani-Kong is actually one of the oldest mechas in the GDI's roster. It was originally created in 1975 by the Americans as a possible deterrant against monsters, only to be critically damaged in a fight against Godzilla in 1977. It was decommissioned for several decades before being acquired and retrofitted by the GDI in the 2040s using the alien technology of the original Mechagodzilla. It was deployed to be a counterbalance to Mechagodzilla II, contrasting with it by focusing more on physical combat than ranged weaponry. In spite of that, Mechani-Kong is equipped with debilitating eye lasers and a grenade launcher. Since the beginning of the crystal outbreak, it has been put back into service, appearing mostly alongside Mechagodzilla II.
 * M.O.G.U.E.R.A. - M.O.G.U.E.R.A. is the only robot in the GDI faction that was not actually constructed by the GDI. Rather, the M.O.G.U.E.R.A. is actually an entire class of mobile weapons platforms created by the Mysterians as war machines, specifically designed to neutralize both the crystals and the alien monsters under the control of the Viras. Each operated by a crew of seven, there are a total of ten M.O.G.U.E.R.A. in the Mysterians' employ, and after the alliance with the GDI, the Mysterians have lent the robots to their human allies. Each M.O.G.U.E.R.A. is equipped with an extensive arsenal of devastating energy-based weapons, but are extremely lacking in close quarters combat.

Aliens
The "Alien" faction comprises extraterrestrial monsters that are either allied or under the control of the Viras, a squid-like alien race who control a massive interstellar dominion that is at war with the Mysterians during the game's events. The Viras actually first appeared as antagonists in the 1968 film, Gamera vs. Viras. They seek to wipe out the Mysterians and become the galaxy's supreme power by harnessing the crystals. Special emphasis is placed on their skills in genetic engineering; a number of monsters in the game, as well as some of the weapons that comprise their war machine, were created by the Viras, who have even found ways to integrate energy from the crystals into them. According to information supplied in some of the monsters' character bios, other alien races are a part of the Viras' empire, occupying a rigid caste system going all the way down to slaves.
 * Gigan - Considered to be the hammer of the Viras invasion forces, Gigan is a frightening fusion between organic and synthetic components. From studies by the GDI, he is at least 12,000 years old, and was created through a grisly process where an entire organic species was broken down into a biomechanical paste and fused with an artificial intelligence. It is unclear who built Gigan, but he was confirmed to have come to Earth under his own power in the distant past. He was defeated by Mothra, then laid dormant until discovered by the GDI in 2032. He awakened spontaneously and after briefly laying waste to the city of Bucharest where he was being studied, he left Earth and flew off into space. The Viras eventually discovered him and placed him under their control so that he could be used as a weapon in their conquest of Earth.
 * Both the Showa and Millennium incarnations of Gigan are playable in the game. Unlike other monsters who have alternate playable renditions in the game, the existence of the two versions of Gigan are addressed in-game. The Millennium version is an upgraded version of the Showa rendition created by the Viras after Gigan was critically injured in a fight against the Titans.
 * Guiron - An alien creature with cybernetic enhancements, including an enormous bladed head that can fire various energy attacks. Guiron was originally a simple animal from the Viras homeworld who was enhanced with cybernetics as part of an attempt by the Viras to recreate the process that led to the birth of Gigan. Guiron features an original design completely original to the game, capable of alternating between a quadrupedal and bipedal stance.
 * King Ghidorah - Arguably the most powerful monster that the Viras have under their control, the three-headed King Ghidorah is an alien super-being whose kind have plagued the cosmos for untold eons. The Ghidorah under the control of the Viras is actually the second individual of the species to have visited Earth. The previous one invaded the planet under its own power in 1991, and in a dark event known worldwide as the "Titan Crisis", it was able to override Godzilla's dominance over the Titans and lead them in an apocalyptic global rampage. Ghidorah was eventually defeated in a destructive battle that pitted it against Godzilla, Mothra, and Rodan in Boston, where it was killed. It's remains were later used to contsruct Mecha-King Ghidorah. This new King Ghidorah is much younger but just as powerful, and the Viras hope to use it to gain control over the rest of Earth's monsters.
 * Two versions of King Ghidorah are playable in the game: one is based on his design from Rebirth of Mothra III, while the other is based on his MonsterVerse incarnation. Unlike other monsters in the game who have different playable renditions, both Ghidorah's have the same moveset.
 * Legion - The Legion are a race of silicon-based insectoid creatures with a hive mind intelligence run by queens. Each queens is gargantuan in size, and powerful enough to match even the strongest Titans. One Legion hive attacked the northwest extremity of North America in 1996, but were destroyed by the combined might of Gamera and the military in Juno, Alaska. By taking control of a second Legion queen, the Viras now have the species under their control, using them as biological proxies for their wars.
 * Mechagodzilla - The first incarnation of Mechagodzilla was an extraterrestrial war machine built by the Bilusaludo, an ape-like race that, in the 1970s, used it in an attempt to conquer Earth. It was destroyed by Godzilla, and its remains were later collected by the GDI to construct Mechagodzilla II. Meanwhile, the Bilusaludo were eventually conquered and exterminated by the Viras, who used their blueprints of the original Mechagodzilla to create their own version. The Viras' Mechagodzilla is an exact replica of the original with all of the same weapons and abilities, with a few upgrades implemented into its design by the Zetton, a race of engineers living in the Viras' slave cast. The robot is controlled remotely from a small squadron of starships in the Viras' battlefleet.
 * Megalon - A bizarre beetle-like creature, Megalon is unique amongst the monsters under the Viras' control in that it is not an alien at all, but rather one of Earth's Titans. However, he has no love or loyalty to either humanity or his fellow Titans. In ancient times, he was worshipped as a god of destruction by an ancient human civilization that once lived near the Bermuda Triangle which Megalon himself later wiped out. When the Viras first attacked during the crystal outbreak, they attempted to use their mind-controlled King Ghidorah to gain control over the Titans, but thanks to Godzilla, they all ignored it. All except Megalon. Cowed into submission by Ghidorah and the alien monsters, Megalon was easily brought into their fold without the Viras even having to use mind control on him.
 * Monster X - The creature known as Monster X is one of the Viras' many genetic creations, made in an attempt to create their own version of King Ghidorah that could override Godzilla's dominance over the Titans. The resultant creature is a fusion of both King Ghidorah and Virasian physiology, bearing a bone-like exoskeleton and a barbed tail similar to the tri-pronged, bladed heads of the Viras. While unable to control the Titans, Monster X is a dangerous beast in battle and is often paired with Gigan in battle by the Viras.
 * Keizer Ghidorah - Under certain conditions, Monster X is able to rapidly metamorphosize into Keizer Ghidorah, a less powerful but just as formidable beast similar in appearance to King Ghidorah. Unlike King Ghidorah, Keizer Ghidorah is quadrupedal and capable of spewing fire and balls of plasma. Keizer Ghidorah's design in the game is slightly different from his canon appearance, bearing traits similar to Desghidorah, Mothra's opponent from 1996's Rebirth of Mothra.
 * Orga - A grotesque alien/Godzilla hybrid creature, Orga is the biproduct of cooperation between the Viras and another alien race known as the Millennians. In the early stages of their attacks against Earth, the Viras sought to use the crystals in conjunction with the DNA of various Earth Titans to create genetically engineered monsters for their army. The Millennians, a gelatinous race of beings who were among the many races forcibly absorbed into their empire, volunteered several of their own to undergo a procedure where their biomass was combined with samples of Godzilla's DNA irradiated by energy from the crystals. The end result of this procedure was Orga. Unlike most monsters in the Viras' employ, Orga is completely sentient and acts under his own control, and is completely loyal to his Viras overlords. When deployed on Earth, he is often accompanied by a pair of Millennian warships, which he and his kind are able to control telepathically.
 * Viras - Among their armed forces, the Viras have subjected members of their species to mutagens, including energy from the crystals, that have dramatically increased their size, strength, and abilities. There are at least three of these individuals present during their conquest of Earth. Out of loyalty to their empire, these three Viras warriors have forgone their names and go only by their species name. Viras's design in the game is a blend of its classic Showa design and new characteristics implemented specifically for the game. Unlike the other monsters in the Alien faction, multiple Viras can appear in a stage at once.
 * Zigra - Zigra is an extraterrestrial, aquatic apex predator resembling a shark that is native to the Viras homeworld. After being tamed by the Viras in the distant past, Zigra's species are now invaluable war beasts effective in both aquatic and land-based warfare. Although more mobile in water, Zigra is capable of adopting a bipedal stance when out of water.

Mutants
Mutant monsters are creatures that, unlike the Titans, were born through unnatural means. As they exist outside of Earth's natural order, they are not bound by any desire to protect the Earth nor do they have any true loyalties, not even each other. As a result, this isn't considered a true "faction", but more of a categorization. Because of this, players who take control of mutant monsters during story mode are given a wider range of story options.
 * Apex Mechagodzilla - In 2031, the multinational technology supplier Apex Cybernetics attempted to mass produce their own version of Mechagodzilla as part of a technological arms race influenced by the GDI's rise to power. Their Mechagodzilla, which was far more mobile with a balanced ranged arsenal and close-combat ability, was completely automated and run by an efficient artificial intelligence. However, during a test run in Pensacola, Florida, the robot went completely berserk and laid waste to much of the city before eventually shutting down from a power loss. This entire incident was a complete disaster for Apex, and the company was sued for millions of dollars of collateral damage and civilian casualties. This led to the company going bankrupt and its assets were acquired the GDI; their Mechagodzilla, deemed a security risk, was decommissioned and stored away at a facility in Hong Kong. During the crystal outbreak, several crystal formations destroyed the facility and their energies were somehow absorbed by the disabled Mechagodzilla. Its power restored and its AI greatly enhanced, Mechagodzilla escaped and is now a rogue element amidst the global crisis.
 * Bagan - Arguably the most powerful monster to have ever been born on Earth, Bagan is an unusual element in that it is, for all intents purpose, a literal god. Once worshiped as a dragon-like god of destruction in China during the Shang period in the 13th century, Bagan was sealed away in the Himalayan Mountains until he was awakened in 2001, in an incident that would come to be known as the "Bagan Offensive". Bagan laid waste to much of China during that time, but was eventually destroyed by the combined efforts of Godzilla and the three guardians of Yamato: Anguirus, Varan, and Baragon. However, three years after the crisis, Bagan was discovered to not truly be dead, but gradually rejuvenating in his prior resting place in the Himalayas. Since the formation of the GDI, an advanced containment facility was built around Bagan with the intent of keeping him both contained and studied. During the crystal outbreak, Bagan's containment facility was raided and overtaken by the Viras, who sought to put the ancient dragon under their control. By implementing him with the DNA of Godzilla and King Ghidorah, the Viras hoped to accelerate his recovery. They succeeded, but also empowered Bagan to a point where he could not be controlled. Bagan's design in the game is identical to that of his appearance in the 1993 video game Super Godzilla, but with a gray and purple color palette similar to his design from Godzilla Movie Studio Tour.
 * Barugon - A lizard-like creature, Barugon was another ancient creation of the long-lost Gamera. According to records recovered by the GDI, he was an early attempt by the Kilaaks to act as a deterrent against the Gyaos before being discarded in favor of Gamera. In 1998, Barugon's shrine in New Guinea was disturbed by treasure hunters seeking to loot the valuable Kilaak artifacts held there, and the creature was awakened and terrorized the island. Gamera was alerted to Barugon's presence, and after a grueling fight between the two in the ocean, Barugon was criticially injured and instinctively froze himself in an enormous glacier. The glacier remained as it was until it was thawed out by the crystal outbreak, and Barugon is now a rogue amongst Earth's monsters.
 * Battra - A dark counterpart of Mothra, Battra is considered to be one of the Titans, but is hostile to all other monsters. He is stated by legend of have been conceived by the Earth itself in response to mankind's negative influence over Earth's ecosystem. However, many scientists in the GDI are skeptical of that. Nonetheless, Battra first appeared in 1992 shortly after the Titan Crisis, which did horrific damage to the Earth, and began aggressively targeting human cities. Mothra confronted him in an aerial battle over the city of Yokohama, and the ferocity of their battle drew in Godzilla. The fight ended with Battra badly wounded and left to rejuvenate at the bottom of the ocean, and he would later target mankind again in in the 2040s. This time, he was faced with the GDI's mechas, and was easily outmatched and incapacitated by Mechagodzilla II. He was held in a cryogenic suspension facility on Monster Island, only to be awakened when the crystal outbreak damaged the island's containment facilities. Still seeking to protect the planet, Battra has begun targeted the crystals, but still has no loyalty to mankind or any other monster. Unlike Mothra, Battra is capable of transitioning between his larva and imago form at whim.
 * Biollante - Biollante is a monstrous plant/Godzilla-hybrid creature that was created by Dr. Genishiro Shiragami, one of the GDI's leading geneticists and experts in the Titans. During the crystal outbreak, Shiragami was charged by the GDI with finding a way to curtail the spread of the crystals, and he created a foam compound consisting of mineral-consuming, plant-based microbes artificially synthesized from Godzilla's DNA and the DNA of a rose to seek out and consume the crystals. Instead, the foam ended up fusing with the crystals to form Biollante. Confused over her own existence and place in the world, Biollante has no immediate loyalty to any existing faction, but is not considered overtly hostile unless provoked first. Biollante's rose form is encountered as a mini-boss in the game's story mode.
 * Destoroyah - Destoroyah is a malevolent entity created by a colony of crustaceous organisms originating from the ocean. There is a scientific explanation that these organisms were mutated by the Oxygen Destroyer, a chemical weapon that had been used against Godzilla in 1954 during his initial rampage through Tokyo. The device, which was lost in the attack, was capable of vaporizing oxygen in water-based environments through use of an unstable compound called micro-oxygen. After it was fired in Tokyo Bay, the soil on the ocean floor was contaminated by micro-oxygen; the colony of microorganisms that eventually became Destoroyah were able to survive the contamination and incorporate micro-oxygen into their biological processes, giving them abilities similar to the Oxygen Destroyer. In 1995, during the construction of the Tokyo Bay Aqua-Line, the creatures were roused and made their way to the surface where they were discovered by scientists and kept in containment in a laboratory in Tokyo for several years, with many hoping that the creatures could be weaponized as a deterrent against giant monsters. However, during a containment breach, the creatures escaped ten years later and went on a rampage through Tokyo, continuing to evolve until they all emerged into one. Destoroyah was eventually incapacitated by Godzilla, but the fight also shocked the whole world when it left Godzilla himself near death, and he would remain comatose in the ocean until his fateful battle with Gamera in 2023. Surviving samples of Destoroyah were quickly obtained and later made their way to the GDI. Destoroyah was then kept under heavy lockdown in an advanced containment facility situated on Monster Island, far from the habitats of the other monsters, with the GDI struggling to find a way to completely kill the monster. Now, with the crystal outbreak, Destoroyah has escaped to menace the world again.
 * Gaira - Gaira is one of the two Gargantuas, alongside Sanda. In 1965, a gigantic version of Frankenstein's monster was let lose on Japan through a series of events that began as far back as the 1940s, when severed tissue from the creature were acquired by the Axis powers. The creature was eventually killed by the Yamato guardian monster Baragon, and its remains were left scattered around the country. While most pieces of Frankenstein's monster were acquired and destroyed by the military, stray pieces were left undiscovered and gradually reformed into brand new creatures. Gaira, the Green Gargantua, formed from tissue that lay at the bottom of the sea and thus developed an aquatic lifestyle. Due to living in harsher conditions, Gaira is extremely hostile to humans and in fact actively hunts and feeds upon them. In 1971, Gaira and his counterpart, Sanda, fought each other but were eventually stopped by the military. While Sanda remained docile and friendly under human care, Gaira was left comatose and so badly injured that it took him decades to eventually regenerate. Both monsters were eventually transferred to Monster Island, where they would remain until the crystal outbreak.
 * Gyaos - Genetic creations of the long-lost Kilaak civilization that inspired the legend of Atlantis, the Gyaos are largely considered to be one of the greatest banes to not just mankind, but other giant monsters. A race of bat-like creatures with the ability to reproduce asexually, the Gyaos were originally bred by the Kilaaks as a deterrence against the Titans when the aliens tried to colonize Earth. Instead, the Gyaos went rogue, and their threat level prompted the Kilaaks to create Gamera as a deterrent. While Gamera was able to quell the threat of the Gyaos, several eggs survived into the modern day. There have been multiple incidents throughout the decades where Gyaos have appeared in variable numbers, but have always been put down by both the Titans and humanity. They are such a threat to the planet, that a rare kill-on-sight order is issued if the Gyaos ever appear. The energies of the crystal outbreak have unleashed one of the worst Gyaos swarms yet, and the voracious creatures will stop at nothing to obtain power and overrun the planet. The Gyaos' appearance in the game is based on their design from 2006's Gamera: The Brave.
 * Hedorah - An alien organism born from pollution and environmental waste, Hedorah is actually a collection of living minerals, each with a life of its own, that can combine together to form one larger creature. One of the first extraterrestrial monsters to menace mankind, it arrived on Earth in 1979 in an asteroid that originated from the Dark Gas Nebula. It lived off of large quantities of pollutions to the point where it grew large enough to challenge Godzilla, who fought it to a standstill in Africa in until intervention by human military forces unleashed an electrical weapon that tore Hedorah apart. Living samples of the creature were collected in the aftermath and kept contained in sterile environments, and they were later transferred to a research complex at Monster Island, where their growth and evolution were closely monitored. This proved to be a disaster for the scientists at Monster Island, as during the crystal outbreak, the creatures would escape from their confinements and, after being empowered by samples of the crystals that were being studied in the same facility, were able to grow and fuse without the need for pollutants.
 * Iris - The creature Iris is a bizarre, tentacled being that appeared near the onset of the crystal outbreak. Archaeologists working for the GDF that were studying the history of Gamera found a Kilaakian shrine in Japan's Nara Prefecture, which contained an egg that, while being studied by the GDF, hatched into Iris. Much like Gamera and the Gyaos, the creature Iris is a genetic creation of the Kilaaks, though why he was created is largely shrouded in mystery. Multiple theories have been passed around by the GDF: some believe he was meant to be a failsafe against Gamera should he ever go rogue; others theorize he was an early attempt to fight the Gyaos that was ultimately discarded in favor of Gamera. While in captivity, Iris bonded with a scientist at Monster Island whose family was killed in Godzilla and Gamera's battle in San Francisco. Fueled by the scientist's hatred, Iris became hostile and murderous towards other monsters, and in the chaos of the crystal outbreak on Monster Island, it escaped and fed off of several scientists, allowing it to grow to gigantic size. Fueled by hatred, Iris left Monster Island with the intention of killing the sources of its human counterpart's rage: Godzilla and Gamera.
 * Kamacuras - One of Earth's Titans, Kamacuras is a species of enormous insectoids that closely resemble praying mantises, but studies by the GDF confirm that they are a completely unique form of life on its own. They were discovered living on Solgell Island, a landmass in the Atlantic Ocean inhabited by enormous arthropods. While most Kamacuras are confined on the island, rare individuals of the species will often exceed their average size. Two of these individuals were moved by the GDF to Monster Island. When the crystal outbreak occurred, one of them was killed in the chaos, while its enraged mate fled Monster Island. Despite being a Titan, the voracious behavior of the Kamacuras have made them a rogue element.
 * Kumonga - Another gigantic arthropod Titan from Solgell Island, Kumonga is an enormous yellow and black spider. When human explorers first discovered Solgell in the 1960s, Kumonga was the only member of her kind still living. She would hibernate for ten years at a time, waking up periodically to hunt and feed upon the Kamacuras that roam the island. When her presence began to threaten the scientific research outpost established to study the island's fauna, the GDF later had her moved to Solgell Island. Even there, she was proven to be a threat to the other monsters, as she would actively try to hunt and kill them. This required her to be confined on a separate island. Escaping during the crystal outbreak, Kumonga, like Kamacuras, is a rogue amongst the other Titans due to her aggression and ravenous behavior.
 * Megaguirus - Megaguirus is a mutant hybrid of Godzilla's DNA and the Meganulon, a species of man-sized, eusocial dragonfly-like insects from the Carboniferous period. She was created through a series of events in the 2030s that stemmed from the Dimension Tide, a wormhole-generating device that was designed by the GDF as a possible deterrent against giant monsters. The device proved to be a failure after an attempt to use it against Godzilla in 2037 ended with it destroying an oil refinery in Central America. While the Dimension Tide was decommissioned, its use left a tear in spacetime. While the tear has since vanished, it ended up allowing a group of live Meganulon access to the present day. These creatures briefly terrorized.
 * MUTO -
 * Sanda
 * Shin Godzilla
 * SpaceGodzilla
 * Zilla

Trivia

 * The game's subtitle is a reference to a scrapped Godzilla film from the early 1970s titled Godzilla vs. the Space Monsters: Earth Defense Directive. The film was eventually replaced by Godzilla vs. Gigan (1972), which followed a similar premise.
 * Gamera's origin in the game is synonymous with his origin in Shusuke Kaneko's Heisei trilogy in that he was a genetically engineered being created to fight the Gyaos, but with one significant alteration. In the films, Gamera was created by the lost city of Atlantis, but here, he is a creation of the Kilaaks, an alien species that appeared in Toho's Destroy All Monsters (1968). This was to better interweave Godzilla and Gamera into the game's story. Nods to Atlantis are still made, however, with the Kilaaks having inspired the legend.
 * Anguirus, Varan, and Baragon's status in the game as mystical guardian monsters is based on their origins in an early concept for Godzilla, Mothra and King Ghidorah: Giant Monsters All-Out Attack, with Anguirus and Varan filling the roles that would ultimately be filled by Mothra and King Ghidorah.
 * Kiryu being built around the skeleton of a Godzilla found in the Philippines is a reference to "Dagon", a relative of Godzilla whose fossilized skeleton is found in the same location in the 2014 Godzilla film.
 * The Zetton, an alien race mentioned briefly in Mechagodzilla's in-game bio, is the name of an alien species that features prominently in the Ultraman franchise.
 * Gigan's revamped origin in the game is similar to how the Reapers are created in BioWare's Mass Effect franchise.