Isn't it something that the first Duke started out as a children's game on affordable computers? What's even more remarkable is that it was a fun platform game: the result of perfecting the platforming engines and gameplay of Apogee's and Id's earlier installments like Commander Keen and BioMenace. The incredible thing about Duke 1 is that its hero resembled very much the heroes from Secret Agent and Crystal Caves, except his skin wasn't gray, and the gameplay of Duke 1 was a beefy update on both games. Apogee made the most of this engine's EGA colors and sprites, and it shows. It also betrays a very Terminator influence upon its setting. To think that 3D Realms would transform this mainly child friendly game into a much more adult game upon its conversion to FPS. Duke would never be the same again, and he would have ascended further if it were not for DNF's tragic development.
Duke in the demo sequence promotes how it has smother scrolling than the Sega Genesis. Duke had an an internally built engine that was also used in the math and word rescue games and Cosmo used an upgraded engine that went on to be used in DN2. Duke grew up with his audience. the only id code apogee used in the cosmo/DN2 engine was the music code since both games have IMF music files to play on adlib cards.Duke nukem was aimed at older players while keen was for younger players.