One more interesting (and active!) project, see screenshots on their site GitHub - Mon-Ouie/ray: A Ruby library for games — supporting audio spatialization and 2D (and even 3D!) graphics
I recently discovered another interesting option - integration with game via socket. For example, this project GitHub - tinco/RProxyBot: A ruby implementation of the Starcraft Proxybot server (ruby driver for StarCraft 1 from AI Bots competition) uses socket to connect to the StarCraft 1 game and control all the game.
Would be nice to have such thing for games like this:
FLARE http://clintbellanger.net/rpg/blog/20110709 (diablo clone, with very cool graphics) Glest http://glest.org (warcraft 3 clone)
FLARE is especially interesting because it has very high quality art and small and clean source code size.
