Cube was a great freeware FPS featuring an elegant engine. Cube 2, on the other hand, is called Sauerbraten, a word until now reserved for a certain German delicacy, and is shockingly even better (more elegant too). It is also available for free at its official website and, besides sporting quite a few improvements on the eye-candy side of things, the spanking new Sauerbraten engine is quite a flexible beast. Eisenstern the RPG game being built on it, is all the proof you should ever need. And just in case you are unable to enjoy FPSes and engines, well, worry not! You should find enough free games to save you money for a year right here. Enjoy.