Well, this is my first Wario Land, I just played it for a bit, and I think it's a good game. Not great. Just a decent, almost run of the mill, puzzle-platformer. I kind of wish the levels were a bit more linear, so it was a little harder to get lost, but generally it seems to be just about the right difficulty. By far my favorite parts of the game occur after you jump on the frog statue's head, as the races against the clock back to the start are really fun. As for getting to the frog? Eh, those parts are alright, but it doesn't really play like a Nintendo game to me, for whatever reason. It looks like one, what with the wacky powers and all, but it's just not as tight and enjoyable as other comparable Nintendo games. I'll post more thoughts after I play some more.
(As far as what has been said above me goes, I'm with Einstein on this one -- the "feel" definitely hasn't clicked with me yet. Hopefully it will. Also, for anyone who hasn't started yet, I HIGHLY recommend starting with the chamber directly to the right of the intro chamber. It's by far the easiest.)