I went out and bought it a couple days ago (and forgot to post unitl now)
It seems to be a cross between Mario 1, Mario 3, and Mario 64 (Mario 64 mainly because you can do things like wall jump, double and triple jump, ground pound). I personally would have liked it to be more like the third mario (my favorite). The biggest disappointment for me was that you can't play two player like Mario 3 (i.e., alternating play), instead there's Mario vs. Luigi, which is fun, but it's a head-on-head game where you try to collect stars before your opponent does.