To be fairly honest, I would have paid $60 for it.
I mean, hell. My step-mother's baby-sitting rountine just got a lot easier. A boy's on there playing while I can hop in and out.
Wish List: When you make another co-op game this awesome again, could you make it so that we can, while logged into XBL/Profile, hop in and out of the game.
Sometimes he gets into a fight that's rather difficult, so we have to literally exit the game, have me sign in to kick some ass.
And once again, best buy there will ever be on XBL. Better than the actual Teenage Mutant game, plays better than Bionic Command, has more replayability and less annoyances than Braid (That game, as beautiful as it is, doesn't deserve the 94 Metacritic rating.), and doesn't have little tedious game modes that'll only keep you entertained for an hour.
Now, 'cuze me while I try stretch out my thumb muscles. They're locked into the gaming position u,u;;