Chaotic Anitomans (series)

Chaotic Altonians (カオティックアルトニアン) is an overhead beat ‘em up series developed and published by Taito Corporation (and, later on, Square Enix). The main series all have common elements of some humans and a group of Altonians, animals that were transformed into humans, teaming up to take on hordes of biologically engineered mutants (referred to as 'beasts' in Savagery). The games are divided into chapters, each of which culminates in a boss battle against usually massive, terrifying creatures. The bosses in games 1-4 are all named after the scientific names of animals.

Gameplay
Chaotic Altonians can be played by up to three players simultaneously. The objective of the game is to fight against every enemy in order to progress until defeating the boss at the end of each stage before time runs out. The player can choose to play as three of the characters. Along the way the player can pick up items such as first-aid packs to replenish health and poker cards for extra points.

The controls consist of an eight-way joystick for moving the character and three action buttons for attacking. Rotating the joystick clockwise will cause the player character to perform a spinning attack. Pushing the joystick up, down, left or right twice will cause the player character to perform a running attack.

Starting with Chaotic Altonians 2, players are faced with numerous situations in which their action (or inaction) will have an effect on the direction of gameplay. This is exemplified in the opening stage of the game when a civilian is about to be thrown from the bridge to his death. If the player saves the civilian, they will enter the city directly through the gate; however, if the player fails to rescue the civilian, the character is redirected to an underground route through the sewers. If the player rescues all civilians, a secret room full of lives and bonuses is revealed toward the end of the game.

Chaotic Altonians: Every Animal Just Became Human, And I Don't Know What To Do About It! (1996)
In the futuristic Wave City, the insane and disillusioned Dr. Horikawa plans to mobilize his armies of mutants against the unsuspecting populace. 2nd-year student Yamato Ishimori and his Altonian friends set off to his building to stop Horikawa and rescue Yamato's childhood human friend, Maki Fujioko.
 * Yamato Ishimori: The main protagonist. A human who is a 2nd-year high school student. He fears that Altonians would replace humans as the dominant species on Earth and begins to dislike them. But when he hears of Dr. Horikawa unleashing his army of mutants onto Wave City, he had no choice but to join with five other Altonians, who are his friends.
 * Shizuru Kumazawa: A bear Altonian girl with a cheerful personality. She is known to be the happiest Altonian in Wave City until the takeover of Dr. Horikawa's takeover. She, along with four others, assist Yamato to stop the doctor.
 * Makoto Ushiyama: A cattle Altonian who wishes to become a wrestler. She was ready to make her dream come true before the Altonians attacked. She then joined Yamato, as well as four other Altonians, to fight back.
 * Reiji Kitsuyashi: A fox Altonian known to be very fast. He was the best in track and never lost. He saw mutants attacking Wave City and decided to tag along with Yamato and the other four Altonians.
 * Tomoyo Zouji: An elephant Altonian girl who is a scientist. When she heard about the mutants invading Wave City, she saw this as her chance to obtain some samples. She and the other Altonians joined Yamato to help.
 * Yoko Harine: A hedgehog Altonian and the youngest of the group. Mostly carrying her first-aid kit, she wishes to help those in need. In this case, she wants to help Yamato and the other four Altonians as they fight against the mutants.
 * Maki Fujioko: Yamato's human childhood friend who was taken hostage by Dr. Horikawa and his creations. Her fate is determined by how many times the player dies. If the player constantly dies, then the ending shows Maki transforming into a mutant. If the player does not die a lot, then the ending will show her leaving Horikawa's lab with her friends.
 * Dr. Ryoichi Horikawa: An acclaimed geneticist who worked for the Kazari Corporation and the main antagonist of the game. He was responsible for The Wave City Incident. He was obsessed with discovering the creation of Altonians, which eventually drove him mad. His increasingly questionable methods and experiments garnered the suspicion and alarm of his colleagues, until it was too late. His deteriorating mental state culminated in the creation and wanton release of hideous monsters from the laboratory to the mansion and surrounding estate

Chaotic Altonians 2: Every Living Creature... (1999)
Five months later, Hideyoshi Shiraki, the man behind the Wave City incident, claims responsibility. Fueled by his detest of humankind's complete lack of responsibility toward its assigned task, Shiraki initiates a mutant outbreak on Ikebukuro while his Queen project develops. Three new heroes, Kazuya Toramoto, Asuka Ookagura, and Maya Usayomi are sent in order to stop Shiraki.
 * Kazuya Toramoto: One of the three main protagonists. Kazuya is a tiger Altonian who carries with him a grudge against Shiraki. When he hears about the outbreak in Ikebukuro, he joins Asuka and Maya to save the city.
 * Asuka Ookagura: One of the three main protagonists. Asuka is a wolf Altonian who was trained under her father, learning the Sacred Wolf Fist. She joins Kazuya and Maya in their fight against the mutants invading Ikebukuro.
 * Maya Usayomi: One of the three main protagonists. Maya is a rabbit Altonian who is the late heir to the Usayomi line. Unfortunately, she hears about the crisis in Ikebukuro and runs to join Kazuya and Asuka to save the city.
 * Dr. Masaka Izumi: A human doctor who was responsible for sending Kazuya, Asuka, and Maya to Ikebukuro. She is also in the city alongside Tomoki and her invention, the Twindial, to investigate and search for surviving victims.
 * Tomoki Komoumaru: A bat Altonian who is Dr. Izumi's assistant. He is usually clumsy when it comes to rescuing victims and is likely to panic when he sees a mutant. He was even captured by one of Shiraki's creations.
 * Hideyoshi Shiraki: A human man who is the head of an eminent financial group in the world and an expert of the genome theory. He is revealed as the true mastermind behind Dr. Horikawa's inhuman experiment, as well as the beast attack in the 2003 Ikebukuro Incident, where he sought to "revert humanity to Altonians" as a means to "recreate the balance of nature".

Chaotic Altonians 3: Every Altonian Became A Savage, And We're The Only Ones That Can Save Them! (2003)
In an Altonian-dominated Shinjuku, Yamato and his team of Altonians infiltrate the Oni Research Facility in hopes of finding the source of the city's population. Losing contact with him, his friend Maki and her team of Altonians set out on a search and recover mission, unaware that what awaits them has ties to the distant past and the very genesis of the mutant horde. Dr. Horikawa's son Satoshi is also trying to prevent the disaster by destroying the legacy of his seemingly deceased father.
 * Masaru Saina: One of Maki's Altonian companions. He is a rhinoceros Altonian who, despite his muscular physique, is actually kind. Since he is from the same school as Maki, he tags along with her to defeat the mutants in Shinjuku.
 * Eiji Nezunaka: One of Maki's Altonian companions. He is a rat Altonian deriving from the Nezunaka ninja clan. On his outing, he noticed mutants attacking Shinjuku, so he teamed up with Maki, who has visited his house before, to fight them.
 * Hikaru Mogurai: One of Maki's Altonian companions. Hikaru is a mole Altonian who is considered a genius because of his intellect (which almost rivals Tomoyo's). He joins Maki in her battle against the mutants because she helped him with his computer in the past.
 * Megumi Tokasai: Another of Maki's Altonian companions. Megumi is a lizard Altonian who is experienced in playing the viola. Since Maki was a part of Megumi's band, she joins her in the battle of Shinjuku.
 * Aika Saruyori: One of the five Altonians Maki has accompanied with. Aika is a monkey Altonian who is a specified gymnast. She is the only one who is not familiar with Maki, but accompanies with her regardless.
 * Satoshi Horikawa: The son of Dr. Ryoichi Horikawa. His diagnosis with terminal illness eventually became his father's primary motivation to develop the animal mutation. Because of this, he wishes to put an end to the burden his father made.

Chaotic Altonians 4: ...Are Now Monsters (2006)
In the year 2003, Kazuya Toramoto (from Chaotic Altonians 2) and his new group of Altonians are investigating the Shiraki Incident from last year. Following a sudden earthquake, they are shocked to discover that the mutants from three years prior have returned, seemingly unharmed, and locked in a lab, but they soon break out and wreak havoc once again. Intent on preventing a nuclear disaster, they must once again cross paths with the seemingly deceased Shiraki.
 * Vanessa Mallardeen: One of Kazuya's new Altonian companions. She is a duck Altonian who once worked as a bouncer for a night club. She was later assigned with Kazuya to investigate the incident and stop all of the mutants.
 * Stephen Billings: Another one of Kazuya's new Altonian companions. He is a goat Altonian who was formerly a baseball player. During his investigation with Kazuya and the others, he was caught in the earthquake and now has to face the mutants.
 * Lisa Henyen: One of the new Altonians assigned to Kazuya. She is a chicken Altonian who is also a stripper from a small club in Chinatown. She was with Kazuya when the earthquake occurred, forcing her to fight against the mutants.
 * Martha Hippotts: One of the Altonians working for Kazuya. Martha is a hippopotamus Altonian who was an actress on countless movies. She joins the fight with Kazuya against the mutants when she and the others are trapped in the lab.
 * Samson Hawkins: One of Kazuya's new Altonians Samson is a hawk Altonian who is also the boyfriend of Vanessa. He was trapped with the rest of his partners during the earthquake and now must fight the mutants left by Shiraki.

Chaotic Altonians 4: After Story (2007)
Set shortly after the end of Chaotic Altonians 4, Vanessa Mallardeen joins forces with Maya Usayomi in order to destroy the "source" of the outbreak. You fight the Succubus again, giving you the chance to destroy her for the 3rd time.

Chaotic Altonians: Savagery (2010)
In the Winter of 2002, young Shizuru Kumazawa teams up with college student Albert Stevenson to investigate mysterious disappearances in Ireland. Unfortunately, they encounter hordes of mutants there.
 * Albert Stevenson: Shizuru's partner. He has been searching for answers about the death of his father, so he joined Shizuru. He has a habit of swearing a lot.
 * Miss Lovely: Sadistic crime lord Lorise has forced Viktor's sister Lapis into devising a strange compound with mutagenic effects. With the help of Warden Clyde he sets to work transforming the innocent inhabitants of Ireland into mutants and monsters.
 * Viktor White: A handsome bouncer from the Irish Rain pub, Varla is also the older sister to crippled scientific genius Jasper Guns. She joins the agents to stop Miss Lovely, and a love triangle develops.
 * Tony Tora: A young dancer and former lover of Viktor White's younger sister Lapis. After finding out the death of Lapis, Tony joins Viktor to seek revenge against Mis Lovely and together, they fight off the mutants and seek Miss Lovely to avenge the death of Lapis.
 * Warden Clyde Fongri: A strange and unsettling man who oversees a high security prison just outside town, Clyde is involved in gruesome scientific experiments to prolong the life of his elderly mother. He is later revealed to be the main antagonist and mastermind of the events.