List of Luigi's Mansion pre-release and unused content

This is a list of pre-release and unused content for the game Luigi's Mansion.

Early ideas
Different kinds of houses were proposed for the game, including an apartment complex, a dollhouse, a "ninja mansion", a Japanese-style house, a prairie, and a desert level using a Mario theme. The game was originally conceptualized to resemble the Mario series more closely, but strayed when the haunted western mansion concept took priority. The idea of multiple, Mario-esque themed houses would later be used in the game's sequel.

Luigi's Mansion was developed with stereoscopic 3D compatibility. The Nintendo GameCube was built with 3D components which could be activated by an unreleased add-on. This add-on was never released as its price would have been far greater than the console. Another unreleased add-on would have allowed the Game Boy Advance to be used as an external controller in conjunction with the game. The game's remake and sequel both support stereoscopic 3D, as they were released for the Nintendo 3DS.

Early iterations
Concepts for Luigi's Mansion, such as character designs, were being planned during the Nintendo 64's lifetime.

The game was first revealed at Nintendo Space World in 2000 as a tech demo, designed to show off the graphical capabilities of the Nintendo GameCube.

Nintendo then decided to make Luigi's Mansion into a full-fledged game, and was later showcased at E3 in 2001, with notable changes to the design of the disc.

Early builds
Old issues of Nintendo Power (pictured below) contain details of early elements in screenshots and descriptions.

Poltergust
In earlier builds, the Poltergust 3000 originally featured a pressure meter ranging from one to ten, and was slightly bigger. If the pressure meter reached ten, the vacuum would backfire and burst out flames, causing Luigi to fall over and lose health, his HP eventually raises back up slightly after a while. Earlier versions of the game allowed Luigi to spray water infinitely. The Poltergust 3000 also had different nozzles depending on what element was being used.

GUI changes
Luigi's total remaining health was shown as a fraction. Coins also had their own meter. Early builds reveal that Boos captured would be displayed by a whole number.

Originally, the Game Boy Horror had an LCD border, which would function as a red flashing radar to show Luigi the locations of both ghosts and Boos within a room, and had a clock function. One clip shows that once the clock reached 1:30 on the E3 Nintendo Booth version, E. Gadd would contact Luigi and send him back to the title screen. Early gameplay images reveal that instead of showing Luigi his current gold total, the Game Boy Horror would always display a first-person view camera, giving the player two perspectives in a room at once.

Early ghosts

 * There were ghosts in earlier versions that were similar in appearance to Gold Ghosts. They would attack Luigi from behind by going "BAAHHHHH!", causing Luigi to scream, crawl backwards uncontrollably, and lose a large amount of HP, while the denominator of his health guage changes to 50. Luigi's HP raises back up after a while and his heart would beat fast on his health gauge.
 * In earlier versions of the Kitchen, a ghost resembling a chef would have appeared while holding a tomato.

Other

 * The game had a different main menu, giving the options to "Skip Intro" or play "From The Beginning". E. Gadd also had different dialogue.
 * The cutscene showing Luigi walking to and opening the door to the mansion was slightly different. The door was also designed differently.
 * Ghosts had a different sound effect when appearing upon from behind the player, instead of the final scary, loud scream from behind in the final. Ghosts also didn't startle Luigi upon appearing.
 * The Gallery had a different design than the final game.

Unused models
There are three renders of Luigi left in the code for the ending, each with a varying degree of happiness. The renders are a depressed Luigi holding a flower (worst), a pleased Luigi with a peace sign (good), and another pleased Luigi with two peace signs (best). An unused model for Mario, labeled "bmario", is stretched to Luigi's proportions and given the backstraps for his Poltergust 3000, possibly suggesting that multiplayer was originally planned.

Cyan and blue-colored Ghost Guys are also in the game's data.

In the game's data is also the unused Poltergust 3000, along with two unused nozzles; one of them is labeled "wpwater".

Other

 * There were two unused early ghost designs:
 * A blue ghost, Obake01 (thought to be an early Gold Ghost)
 * A green ghost, Obake02 (thought to be an early Purple Puncher)
 * There were four unused dialogue icons:
 * Bowser
 * Green Toad
 * Gold Ghost
 * Mario (missing when Mario talks to Luigi at the Bottom of the Well, while trapped in the Secret Altar, even in the early Nintendo 3DS remake)
 * There were four unused text strings suggesting that E. Gadd's Lab was once explorable (the Gallery is explorable, although its associated area text seen upon entrance in the final is unused):
 * Underground lab
 * Gallery
 * Training Room
 * Ghost Portrificationizer Room

Multiplayer
On June 26, 2019, a modder by the name of KIRBYMIMI was looking through the code for Luigi's Mansion specifically for files referring to Luigi. One file referred to the quantity of Luigis that can be present in the game, and adjusting it would cause a second Luigi to appear, though without a Poltergust. By adjusting other coding to account for this second Luigi, it became possible for a second player to control this other Luigi. This Luigi shares the same animations as the original Luigi, but has difficulty opening doors and cannot pick up objects. The second Luigi also can move during the cutscene where E. Gadd is introduced, and suck up ghosts if the Poltergust was manually added. If the two Luigis move away from each other, the screen splits horizontally and the game does this automatically, meaning the multiplayer mechanic existed within the game's files. Additionally, the second Luigi is able to vacuum the same ghost the first Luigi is vacuuming. This multiplayer experience came to fruition with the inclusion of Gooigi, who shares some of the same coding and limitations of this second Luigi, in the game's Nintendo 3DS remake.

Trivia

 * The Japanese version of the game kept Luigi's early or cut hurt sound, while U.S. and European versions didn't.
 * The Game Boy Horror's timer and first person view is still in the game's code for all regions and has been found and made into Action Replay codes.