"Wow you guys" is exactly right... it's a gift. from a 10 year old, no less!
i got super monkey ball and elebits as gifts from a very close friend. neither received more than 30 minutes of gameplay, but i still kept them. even with etiquette aside, when its about close friends and relatives, you pretty much have to keep those gifts since they will come a time when they come to your home and they'd be very upset if they don't see that gift. your reputation takes a plunge, the friendship and mutual respect take a plunge, $60 is certainly not worth that.
on another instance, i did return for store credit for one game--it was a game i already had. so, again, etiquette aside, you'll never "get caught" (unless that gifter happen to be in the store when you're returning it for store credit). plus, the gifter had included the gift receipt and in addition, because of the circumstances under which the gift was given (a little business-like), is certain not to be offended.
the Wii is an epidemic.
