Prior to it's 2011 release, Duke Nukem Forever went through various different stages of development. The 1996 build of the game had a completely different style of gameplay compared to other builds of the game, where the game was intended to be a 2D side-scroller instead of a third person shooter.
On December 26, 2022, 4 prototype builds of the game was leaked onto 4Chan by x0r_jmp.
at://did:web:gamesgamesgamesgames.games/games.gamesgamesgamesgames.game/3mgkupyli7t2l