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.
Different kinds of houses were proposed for the game, including an apartment complex, a dollhouse, a 'ninja mansion', a Japanese-style house, and a prarie and 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 originally built with the intention of being in stereoscopic 3D. The 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.
Old issues of Nintendo Power (pictured below) contain details of early elements in screenshots and descriptions.
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 burst into 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.  The Poltergust 3000 also had different nozzles depending on what element was being used.
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. It was cut due to the Nintendo GameCube's hardware not being able to handle it. 
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, named "bmario", is stretched to Luigi's proportions and given the backstraps for his Poltergust 3000, possibly suggesting that Multiplayer was a thing originally. 
In the game's data is also the unused Poltergust 3000, along with two unused nozzles; one is labeled "wpwater" and appeared when
Game Boy Horror build
Unused Dialogue Icons