Duke Nukem 3D was released exclusively in Brazil, with gameplay remaining largely unchanged from the original. Players blast invading aliens from Duke's perspective, navigating through nine levels based on the PC's Lunar Apocalypse episode. The game features a range of enemies and weapons, but the difficulty has been increased significantly, while the framerate is noticeably reduced. The port also employs scanlines and a smaller window size to reduce the render load.
The gameplay in Duke Nukem 3D involves shooting and fighting against various aliens and other enemies, with an emphasis on action and adventure elements. Players control Duke as he explores the nine levels, collecting power-ups and trying to defeat the alien threat.