Back in 1993 & 1994 I did a lot of computer art with Animator Pro for the PC computer game 1830, SimTex's computer version of the Avalon Hill railroad strategy boardgame (for which I was also lead programmer). I did all the hex tiles for railroad track and mountains which had to match up in all possible combinations. 26=64 different mountain tiles which needed to verifiably all fit together... Same story on the couple hundred different track tiles which needed all 6 orientations for each! This was at least as much a math puzzle as an artistic endeavor, which I guess is why 3 different artists quit doing it and I ended up doing the mountain tiles!
I also did the stock certificate art and a few other bits of art in the game. The rest of the game art was done by real artists. :)
It was frustrating that our library at the time was still lo-res, but given the constraints of a 320x200 (or was it 240?) screen, I think it all came out all right...