Had it since Monday night. I am on World 5 so far and love it. Even though there is no Racoon/Tanooki power ups, gameplay is as close as a modern sequel can get to SMB 3 and the level structure is nicely refined.
Collecting star coins opens up challenging yet leisurely replay value. Blue turtle shell and micro Mario are ace IMHO and both encourage extra exploration within the levels. Only down side to the blue shell as others have said is you will spin off a ledge sometimes. Anyways, great game so far and it's nice to see Nintendo and Tezuka release a sequel which has also brought back great memories for me of my old NES days. Plus later we can look forward to Super Paper Mario. Good time to be a 2D Mario fan.
edit: Oh yeah, and the 1Up review was lame. Although I often disagree on some things he says, I normally enjoy Parish's writing. But he was in complete snob mode on this one. I said this elsewhere and I will say it again: when a gaming geek/reviewer (Parish) refers to
himself as the teacher, and a Tezuka/Miyamoto product as the
student, well folks...that isn't
quite what I'd call proper "geek protocol/ettiquette" to put it mildly. He writes the review in the tone of a classroom setting and at the end of the review he says: Parish- "Nice try NSMB, but no gold star. Please see me after class." Hmmm.