If you didn’t already know then you might be surprised to learn that Doom creators ID Software created their very own Super Mario Bros 3 demo on the PC. The demo was created to entice Nintendo to bring the game to the PC. Obviously this never happened and instead the project turned into Commander Keen. This is the very first time we’ve seen footage of the PC build of the game created by John Carmack and John Romero and you can check it out, below
This is a demo of IFD’s (soon to be id Software) Super Mario 3 demo created for Nintendo on the PC. The demo was completed on September 28, 1990.