I picked it up on special at K-Mart and am really enjoying it. I'm waiting to unlock a lot more stuff before I start playing around in the creator (yes, it's that kind of game unfortunately), but the gameplay "feels" right, except for the grab tool which I'm yet to master.
Once I get further into it I will start to create stuff and we can talk sharing levels.
I bought it the other day as stress relief after a particularly nasty exam.
Multiplay is great, especially the Jenga style grab game. Blowing stuff up is always fun too. The only bits I don't really like so far are the 'protect the gems from thieves' levels.
It's on my "Buy as soon as I grab a Wii" list. I think I may also buy a copy for one of my friends with a Wii...not entirely altruistic, that, as they tend to bring their games to parties.