I agree about Sonic Rush being a great game, but after playing it I didn't decide to buy it for the same reason I didn't buy NSMB.
Both feel like small experiences where the replayability is just playing the game over and over again and I think there are lots of other games I wanna play that have a lot more to them than just that experience, including on the DS.
Don't get me wrong, I thought both were great as rentals but not something I would buy because I don't feel I get enough out of it beyond the relatively short experience that is fun but not as good as other games out there.

Thanks to Blacksaber for the sig!







