I gotta give the devs credit: the idea of taking Guitar Hero with you on the go sounds pretty cool in theory. In practice, though... it just doesn't work that well. The peripheral you plug into the GBA slot of the DS to simulate holding a normal GH controller is kind of a neat idea, but I can't imagine it being comfortable to use for very long. And unless you're using headphones it's just hard to "rock out." An odd little novelty in the GH lineup.