Luigi's Mansion Online

Luigi's Mansion Online is a online multiplayer action adventure game in the Luigi's Mansion series developed and published by Nintendo. The game follows Luigi, Mario's brother, having to rescue the scientist E. Gadd from his captivity in the mysterious ghost realm and from the schemeing King Boo. The game is notably darker than previous Luigi's mansion games.

Plot
The game opens on a stormy night at luigi's home, the plumber is down on his luck, with his home falling into disrepair seemingly due to a lack of money and a greedy landlord. Bringing plumbing tools and a flashlight to his bathroom, Luigi attempts to fix his shower by unscrewing one of its pipes. What happens instead is a burst of baby spiders out the top of the pipe which frightens Luigi. Luigi gets back up but hears strange noise coming from the shower's pipe, then a bulge forms in the pipe and slowly and suspensfully climbs up it to Luigi's terror. Out the top comes a spider robot belonging to no other than E.Gadd who's here to call upon his old friend for help. E.Gadd appears on a oversized monitor from the spiders body, he explains his disastrous experiment involving a portal to the world of ghosts and the looming threat of King Boo who he is hiding from. The shower drain unwillingly sucks Luigi down it in a whirlpool fashion with polterpup following, taking the two to E.Gadds new laboratory.

Both are spit out the other end and its revealed the thing sucking them down the pipes was none other than a greenie with a new model of the Poltergust, who leaves into the next room through a wall along with polterpup. Luigi goes through a large metal automatic door in front of him that takes him from what looks to be a broom closet into a lab room with a large screen and smaller monitors. E.Gadd explains that in order for his rescue, Luigi will need to find the same six haunted treasures that powered his machine. The treasures however have been warped to the most haunted locations in the mushroom world, where Luigi will have to battle ghosts and collect said treasures from bosses. This time Luigi won't be doing it alone though, E.Gadd has created a Luigi cloning machine in order to find the treasures which scares luigi. The greenie hands Luigi the Poltergust and a tutorial is offered. After this luigi is allowed to travel to the six locations.

After the treasures have been collected Luigi and the ghosts repair the portal and the Luigi, along with others if one choses, enter. In the world of ghosts King Boo had built a maze of physical and psychological torture the Luigis/luigi will have to endure to rescue the now believed to be kidnapped E.Gadd. First, Luigi will have to hide in the shadows of a giant Mario while exploring a twisted version of 1-1 from the original Super Mario Bros. Then he will have to escape a ominous but slow blue shell while running laps around a dangerous go-kart surrounded by spikes and littered with car crash imagery. Luigi will then have to face a Daisy statue that can turn whoever displeases it into stone, Luigi will have to find the right gifts for the statue and use the other ghosts looking to please her as clues. In the next room, Luigi is in a giant baby crib while Kamek rocks it violently, potentially causing you to fall out along with the falling skeleton goonies. The last trial that Luigi faces is a hall-of-mirrors race with Waluigi. Luigi thinks he had finally found E.Gadd only to be ambushed by boos, these boos form Boolossus, one of the bosses fought in previous Luigi's Mansion games. This time the boo's have been training since their last defeat and now take on a more horrifying form when fought, with a very realistic uncanny valley appearance, Boolossus is also fought in near pitch-black darkness with only flashlights providing light.

Boolossuses defeat brings Luigi back to E.Gadds lab, where he and company can chose to enter the portal again and fight the final boss, King Boo. Once the portal is entered Luigi finds himself in a dark room with E.Gadd standing alone in a spotlight. Luigi rushes over and tries to grab him, but instead finds himself covered in baby spiders like in the in the beginning of the game. Then glowing eyes emerge from the darkness belonging to King Boo himself, to which he taunts Luigi and then illuminate the massive arena the two are in the middle of. King Boo is battled on a platform that travels lower into the arena with each phase ending in a place resembling Hell complete with fire and devil ghosts. King Boo is defeated and the arena goes back to being as dark as before with a spotlight appearing over the real E.Gadd who Luigi rushes over to, the two are glad to see each other and share a moment. E.Gadd reveals that he just learned the ghost realm was a prison and that King Boo was being held prisoner there, and that the haunted treasures can allow him to escape and terrorize the mushroom world again. The ground beneath the two shakes and begins to form cracks, then a portal opens with the haunted treasures falling out. King Boo is shown to be the one busting through the platform from beneath and pulling the treasures from their place. The portal begins to fade but a rope hangs out allowing for escape. The two along with two other clone luigis' grab the treasures and hang on to the rope and ghosts in E.Gadd's laboratory attempt to pull them out. A problem is faced when all the clone luigis' and E.Gadd are too heavy to be pulled up. E.Gadd chooses to let go of the rope as he had conciously choosen not to carry any of the treasures. E.Gadd falls towards the Boo King's mouth still wearing his smile, before he falls in Luigi is pulled out. Polterpup and the other ghost from Luigi's Mansion: Dark Moon are there to celebrate their return and mourn the loss of E.Gadd. A party is thrown and at the very end ghost E.Gadd emerges and thanks Luigi silently. After this the player can collect the treasures again and again to play a difficult bonus game with randomly generated rooms similar to the ScareScraper.

Gameplay
The game plays nearly Identically to Luigi's Mansion: Dark Moon though now a more fleshed out upgrade system with choices and upgrade slots. Online play can allow for up to 16 other Luigi's to play simultaneously in the same locations, with groups of 4 for teams of players. The game gets much more difficult toward the end so team work is almost nessecary. Fighting bosses now has a queue and so does certain areas. There are now minigames that can be played at E.Gadds lab cooperatively and a challenge mode. Costumes are also unlocked for Luigi using boo coins, a new currency earned for capturing boos. Locations are all divided into rooms where ghosts are encountered, if a player/players on one side of a door encounters a enemy then the doors into the room are unenterable until whoever inside defeats the ghosts. Missions are also available to players to earn gold.

Worlds
The worlds in Luigi's Mansion Online are all inspired by real world haunted locations. Some are not even mansions and instead wide open areas.
 * Maze Manor- The first world of the game inspired by the Winchester Mystery House. Hallways, doors, and stairs that lead to no where will have to be navigated. Watch out for shifting corridors and crushing walls. The boss here is a minotaur-like ghost with a antique helmet on its head whose fought in the dark cellar maze beneath the mansion. The haunted treasure here is a skeleton key.
 * The island of missing toys- The second world of the game, based on the Island of the Dolls. Forgotten toys decorate the island, some hanging from trees. The whole place is infested with spiders and the final fight of this world is against a large spider inside a doll. The haunted treasure is a string doll.
 * End of the line inn- The third world of the game inspired by the Henry Plant Hotel. The architecture here makes this reference more obvious as does the railway themes and swamp setting. Dangerous railway equipment has been left in the open for Luigi to harm himself on as well for the ghosts to use as weapons, skeletal crocodiles are also a threat when wading through flooded hotel rooms and railyards. The boss here is a ghost train that has been given a horrifying fire-breathing face by its cute ghost engineer. The haunted treasure is a railway spike.
 * Prehistory pools- The fourth world of the game, inspired by Mimaland. Luigi traverses jungles, stitled huts, waterslides, and most interestingly, decrepit dinosaur statues. The place is full of safety hazards from before the park shut down, like broken slides and dangerous weeds that will pull you down into the water and drown you. The boss here is a swan boat that transforms into a shark, the player battles the shark on a raft instead of how they normally have been handling bosses. The haunted treasure is a dead flower.
 * Living Dead Row- The fifth world of the game, inspired by alcatraz. The prison is infamous for its use of torture methods considered barbaric by the standards at the time, thus its closure, the remains of these brutal scenes can still be encountered inside. Stealth will need to be employed here to avoid the guards who want to give Luigi a similar fate to those who once were imprisoned here, staying away from lights is the way of going about this. The boss is a electric chair with a electric ghost who rides it like a throne. The haunted treasure is a spoon.
 * Scary Library- The sixth and final world of the game, inspired by the Willard Library. The verticality of the place is the most formidible aspect with long falls being possible for uncareful players. The boss is a librarian who unfortunately fell to her death and now has a hatred for ladders, which she destroys to inconvience the player in her Donkey Kong style boss battle. The haunted treasure is a bookmark.

Trivia

 * The first haunted treasure is a skeleton key, Luigi's favorite item in the first Mario Party game.
 * E.Gadds laboratory has references to previous games, like ghost potraits, ghosts from dark moon, and Poltergust models from the games before.
 * The Maze Manor boss resembles a bully from Super Mario 64.
 * The island of missing toys boss resembles mimi's spider form from Super Paper Mario, the doll the spider lurks inside of is also dressed as a maid.
 * The island of missing toys has merchandise from the mario series hidden throughout.
 * Prehistory pools references the environments found in Super Mario World, even the dinosaur statues are colored in a way to reference the dinosaurs from that game, with the grey triceratops statues resembling Reznor and the bright green T-rex statue resembling Yoshi, the T-rex even has orange arms, a detail later removed from Yoshi's design.
 * Living Dead Row has a dry bowser skeleton hidden in one of its cells.
 * Living Dead Row has a scene with 2 skeletons, one skeleton holding a wand, and the other with its bottom half transformed to bricks, referencing Super Mario Bros. similar happenings with toads.
 * Living Dead Row has realistic skeletons for whatever reason.