Unigine started to pre-sale OilRush
It's an RTS like game with up to date graphics engine and really interesting gameplay. There is a Linux and a Windows version. I tested it on ATI HD4770 and it works fine at 80-100fps with the binary drivers. Doesn't work with the open source ATI drivers :(
Anyway for ~‚Ç¨14 there is not much to do wrong (like once going to the cinema).
The game is still in developement but the tutorials, campagne and multiplayer is up and running...
screenshot from yesterday: http://ompldr.org/vN25jMg