This game is a zero gravity fps. Basically you are floating around in space with 6 degrees of freedom, shooting people, so you have to learn to think in 3d when you play this, as enemies could come from any direction. It is hard to get across what this game is like in words, so here's a video someone made:

If anyone wants to try it out, I have steam guest passes, so PM me if you are interested. (Make sure you have a good video card, though, it needs an 8800gt/hd 3870 to be playable on low resolutions and detail)