Just beat this getting all the red gems on every level. Been playing it in small bursts for a few weeks now. Overall thought it was a great little platformer. Good physics, graphics, level designs if you go for all the red gems, length.
My only complaints are that the first 5 or 6 worlds are a joke in difficulty and thus kind of pointless outside a few levels. World 7 is a good difficulty and World 8 is a nice challenging platform that gets your hands sweaty; so those worlds were great. The rest were fun but way too easy. The other complaint I have is lack of real bosses. Fighting the same boss with the same pattern every world (an easy pattern) is zzzz. Some other powerups would've been nice, but I understand they're going for more of a SMB1 game than a SMB3+ game.
Was cool, don't remember NSMB enough to figure out which I liked more. Why haven't they made another Mario for the DS btw...it's been a while and DS is only Nintendo's best selling system......hmmm.
Shame Nintendo is stupid and litigious and keeping this from the US. It's a B/B+ game that definitely worth about $30.