With id Software's classic PC side-scroller Commander Keen celebrating its 25th anniversary, John Romero has posted footage of a project he, John Carmack, and the rest of the id Software team (called Ideas From the Deep) worked on all the way back in 1990. That project? A PC port of the Nintendo classic Super Mario Bros. 3, that they used to try to persuade Nintendo to release the game on PC. It didn't work, but now we've got some footage of the port in action.

Super Mario Bros. 3 Demo (1990) from John Romero on Vimeo.

And apart from the pretty awful sound, which is par for the course for early PC gaming, what we see is pretty impressive. Built from the ground up with tech that would later make its way into Commander Keen it solved a lot of issues PC games had with smooth scrolling on EGA adapters. And in action this port certainly looks like Super Mario Bros. 3, albeit with some slightly off character movements and limited animation. Plus, Mario has these weird black eyes.

Anyway this is a fascinating part of PC history, as id Software would go on to define PC gaming for a large part of the '90s by continuing to push technology as seen in titles like Doom and Quake.