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. Later versions of the game had the pressure meter be updated to a "Ghost Counter", which, truthful to its name, counted ordinary ghosts, portrait ghosts and boss ghosts.

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 from newer builds reveal that instead of showing Luigi his current gold total, the Game Boy Horror was subsequently altered to always display a first-person view camera, giving the player two perspectives in a room at once.

Early ghosts

 * Variations of a ghost similar in appearance to the final game's Gold Ghost existed in an earlier build. They would attack by scaring Luigi from behind suddenly while releasing a "BAHHHHHH" particle, causing Luigi to scream, crawl backwards uncontrollably, and lose a hefty amount of 50 health points while the amount of his maximum health also gets capped to its half; the heart beating very quickly on the counter. After a while, Luigi gets up and his health limit is raised back to normal.
 * In earlier versions of the Kitchen, a ghost resembling a chef would have appeared while holding a tomato.
 * A spherical ghost was seen briefly in the game’s E3 2001 trailer, and was originally supposed to harmlessly bounce around Chauncey's room.

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 game's data 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.

Textures for cyan and blue-colored Ghost Guys along with two unused, non-functioning actors for them are also present in the game's data.

The unused Poltergust 3000 along with the larger equipment still exists as well, along with two unused nozzles used for dust and water labeled "wpair" and "wpwater" respectively.

Other

 * There are two unused graphics for early ghost designs reminiscent of the Spaceworld 2000 tech demo:
 * A blue ghost, Obake01 (thought to be an early Gold Ghost)
 * A green ghost, Obake02 (thought to be an early Purple Puncher)
 * There are 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 are two unseen room name graphics which suggest that E. Gadd's Lab was potentially once explorable:
 * Underground lab
 * 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 routines on memory referring to Luigi. One address/value referred to the quantity of Luigis that are spawned in game, and adjusting it would cause a second Luigi to appear, though without a Poltergust. This Luigi was also formerly inputless, but it became possible for a second player to control this other Luigi by adding custom code which makes him use the second controller. This Luigi shares the same animations as the original Luigi, but has difficulty opening doors and cannot pick up objects. The second Luigi also ignores any commands which take away player input, which means he can walk during most cutscenes; he can also suck up ghosts if the Poltergust was manually added. If the two Luigis move away from each other in a certain distance, the screen splits horizontally and the game does this automatically, meaning the multiplayer mechanic existed within the game's code. Additionally, the second Luigi is able to vacuum the same ghost the first Luigi is vacuuming if timed correctly. 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.