Duke Nukem Forever was released in 2011 with outdated graphics and gameplay compared to its ambitious 2001 E3 trailer. A playable prototype of the 2001 version surfaced, revealing various levels and features, including the Ladykiller Casino and Hoover Dam, but it was unfinished and plagued by glitches. The prototype included navigational puzzles, scripted events, and innovative mechanics like vending machines for healing items. Combat mechanics showed potential, with satisfying weapon dynamics, but the overall experience felt disjointed and less cohesive as it progressed. The prototype demonstrated ambitious ideas but likely would not have stood the test of time alongside classics like Quake or Half-Life.