It could have used some more whimsical dream events to change things up, but over all it was my first real party game for the Wii besides Wii sports and it is, with only a few exceptions, a pretty solid game for what it is... Maybe it isn't much different from the dozen+ other waggle-fest party games, but I've gotta have at least one good waggle game, and I'd rather have a Sonic&Mario one than another...
Incidentally, S&M Olympics was the first game I wanted the Wii for... though I waited until there were a good number of Wii exclusive games I wanted before daring to ask for one. (the others I asked for at the immediate time were Secret Rings and Mario Galaxy)