The 2D, multidirectional scrolling game follows the adventures of fictional character Duke Nukem across three episodes of ten levels each.In the third episode, Dr. Proton escapes into the future, and Duke pursues him through time, to put an end to his mad schemes.According to programmer and co-creator Todd Replogle, John Carmack helped him program some low-level parts of the game code in assembly language.The game's original title was Heavy Metal, but producer Scott Miller hated the name and chose to name it after the lead character, similar to comic books.Apogee successfully fought back, and agreed to use the full Duke Nukem name in all their marketing materials.