i picked up a wii with this game on launch day after much research. Let me just say that I own NES (i got used), N64, Dreamcast, GC, and now Wii. I was getting tired of gaming. I am definitely not a hardcore gamer, and in my precious free hours when I come home from work I don't want to sit around and get fat (that's what TV is for).
Anyway, this game really gets you moving. The mini games are often hilarious (you WILL randomly LOL while playing) and fun. The shooting levels that end each set of mini games utilize the wii controller in the most natural way, and it is immersive and intuitive. I played this game to about 33% completion the first day I had it. This is unusual for me. I figure I'll get about ten hours of gameplay out of story mode if things continue at the present pace. The game gives you an objective early on, and this motivates you to progress through the mini games. I like them so much that I have gone back and beaten the optional 4th mini game in each level I've passed.
I can't speak for any of the other launch titles, but I haven't had this much fun in single player gaming on a console...ever. And all of the mini games and shooting games (you shoot plungers by the way) are available for multiplayer after they have been beaten, although some of them cannot be played concurrently by multiple players.
On a final note, some of the mini games will physically wear you out. Some of the games involving rapid movement (running, cow milking, cow tossing, carrot juice pumping) may require you to catch your breath. If you can't handle this, then you'll be glad to know you can skip one of the mini games in each level. But this physical exertion makes beating a mini game much more gratifying.
I cannot recommend this strongly enough. Get this game.