According to http://www.x.org/wiki/RadeonProgram, Sauerbraten should be playable on my r500 with the radeon driver. I've tried running it with the "-f0" option, but it still says that it's using OGL 1.5 (I think radeon only supports 1.3). It runs very, very slow and is obviously using software rendering. Am I missing some option to lower the graphics even more? I can't even get to the in-game options.