Twitch - a GPL arcade game by David Clark . Twitch is an overhead 2-d shooter, reminiscent of games like Robotron or Tron: Deadly Disks. The player has entered the fortress of the evil Hippopoticus, and is trying to rescue the fair Lady Penelope from his clutches. I wrote Twitch as a proof-of-concept: namely that Python, properly written, is fast enough to create a playable, cross-platform arcade game. WWW: https://sourceforge.net/projects/twitch/