Developer: 3D Realms
Publisher: GT Interactive
Released: 1996, DOS
Duke Nukem 3D is a first-person shooter and the third game in the Duke Nukem series. With its realistic (for the time) city environments, heavy amount of interaction in levels (including the ability to blow up a building and levels that let the player blow big holes in them), and unique weapons, Duke Nukem 3D forever changed the world of first-person shooters.
The game's files contain a whole lotta unused content: Mini-versions of the other bosses that have one health for some reason, an unused flame trap, an unused earlier design for the Pig Cop Tank, a scrapped eating animation for the Enforcer, and more lurk in the files, awaiting someone to tip them...er, find them. And don't even get started on the version differences the game went through...
There are also several prototypes, one of which contains a lot of material that never appeared in any other prototypes nor pre-release media.