Several years ago PCG reported on the early stages of a project by programmer James Lambert, who really loves the N64 and decided for the hell of it to make a version of Portal that runs on hardware first released in 1996.
Well, Lambert is clearly the type of chap who commits to something and then follows through, because he’s spent the time since then continually adding bits and bobs and now has something which, to my admittedly uneducated eyes, is the most impressive homebrew game I’ve ever seen.
As well as a version of steam that ran directly on the console. You could login and chat with your steam friends, if I recall correctly.