“Def Jam Rapstar” is going to be big. At first glance it may just appear to be another music game, just with hip-hop instead of rock music, but it’s really a whole lot more. “Rapstar” may take a few ideas from fellow rhythm game “SingStar,” but, the thing is, there’s an inherent level of competition built into hip-hop, that is going to work exceptionally well in video game form. Add to that the very well designed online community centered around uploading performance videos from the game, and “Rapstar” ends up being one of the most unique (and fun) rhythm games to hit the stores in a long time. Yeah … the kids are gonna love this one.