Interesting title, but folks seem to forget the double-digit MHz processors straining to hit 30 FPS back then on Doom unless it was in a smaller rendering size. This would have killed the performance even on my mighty 486 running at 33 MHz at the time (I don't have a lot of faith in the VM demo). It remains to be seen if the music files are small enough to keep the game to its original ~2 x 1.44MB installation disk size.

Still neat.

I recall Windows 3.1 was sometimes shipped with a speaker driver that could emulate a very basic audio card on a traditional PC speaker almost entirely in software.