Comment by kibwen

For a more modern entrant in the genre of games that are secretly programming, I can't recommend Spacechem enough:

http://www.spacechemthegame.com/

Surely a bit less difficult than Robot Odyssey, but immensely enjoyable nonetheless. I finally forced myself to uninstall it after spending waaaay too much time hyperoptimizing my solutions against the online leaderboard... it was rather addicting. :)