BoingBoing linked to a gamers forum thread: 2008 games in MS Paint. I'm on OS X, so I used Acorn instead. I couldn't register at the forum; first it denied me based on my Gmail address, then once I relented and used another address, it fed me a series of indecipherable captchas until I gave up. So here it is:
And it's based on this:
Not exactly a masterpiece, but certainly a fun challenge. The rules allow you to use a tablet, but I didn't see that til too late.