Ridiculous fun and hilarity; a great launch title!
The premise of the game is stupidly simple; Rayman gets kidnapped by Rabbids and, after each day of trials, is rewarded a plunger (?). Rayman soon realizes that he can use his rewards to escape from his cell. A flimsy premise, at best, that delivers the most solid gameplay I've ever seen. There's a pretty wide variety of mini games that you have to play through, and even though some are rehashed throughout, I found that they became games I looked forward to playing in every day of trials rather than groaning "Ugh, another one of these. . ." I think the best classification of the complexity of these games is right in between Warioware and Mario Party; most of the games are pretty one-dimensional but still require a degree of explanation due to the unorthodox controls.
I'm also a huge fan of the visual style. It's clear that they weren't shooting for something with a ton of detail, but they get characters that are almost hilarious just to look at in addition to the degree of antialiasing and smooth edges they got as a result.
The sound also sets the game apart. The Rabbids and their terrifyingly funny "BAAAWWWWW" noise makes me laugh every time I sit down to play. The sounds within the minigames themselves also match up well with what's happening on-screen, and the music suits the mood well.
All-in-all, I'd chalk this game up to a must-have title for the Wii. Too fun to miss!