There's an of internet phenomenon called the OS-tan. It's a sort of anthropomorphic personification (hello Terry Pratchett!) of operating systems as people. Bootfighter Windom XP SP-2 is a sort of off-shoot of this movement. Only instead of cute girls, the operating systems are deadly mechs. Bootfighter is a fairly easy to grasp mecha brawler, especially if you play a lot of PC games. The controls are effective, the graphics crisp, and the sound clean. The game itself is loads of fun, bringing to mind memories of Zone of the Enders and the battles therein. As it's freeware, it never hurts to try it out if you are curious.

[Via LithiumLeaf]