There's very little fanfare for this XBL game, but I tried the trial today and it's a pretty decent little shooter. It's kind of like UT lite, but at only 800 points, I'd say it's worth it. You can play as all three classes in the trial, and while they're all similar, I feel there are enough difference to merit a preference.
Considering how much I spend on booze and smokes on the weekends, this is hardly expensive. Check it out.