^meh, that's not a problem for most of us. It's your average GoD-sized game, about 5gb. You can always delete it and reinstall at a later date.
Disc or GoD, this should be the first game that every Kinect owner gets: Gunstringer, Fruit Ninja, plus the free Wavy Tubeman Chronicles Troma Live Action Old School DLC Game can't be beat. (I would have preferred paying for it to get some funny achievements, but free is ok)
It's not for the young kids, though. This is a real game for real gamers. Moms, little girls, and Madden Bro's need not apply.