Wario Ware smooth moves is everything you'd want from a Wii party game: crazy, fast paced and diverse.
The good part with Wario Ware is the art direction it has is done in a good way and therefore the Wiis graphics chip doesn't hold it back in presentation. Most of the minigame are well made and look good in the context. The sound and music of the game is also well made and I often found myself digging the tracks when playing through the single player experience.
The single player of the game takes you through somewhere near 10 sets of levels where you have to complete somewhere around a dozen micro games plus a boss game that marks the end of each level. Though the later levels proves to be kind of hard on some parts anyone should be able to play through the game within 5 hours at the single player mode. Although the game let you play through the levels more times with added micro games and higher difficulty and a couple of mini games (like a balloon fight game where you flap the mote and nun chuck to fly through the levels).
Where WW:SM really shines is in the company of others. The multiplayer section is unlocked through beating the whole single player "campaign" and offers four diffrent game modes. All of the modes can be played with a single Wii mote which is passed on between the 2-12 players which adds for the frenzy of the game. Plenty of fun, just watching you friends squatting or lifting the weights in seconds.
As conclusion Wario Ware is a well thought out game with a good number of mini/micro games for the Wii. Many of the early games for the Wii have been mini games heavy, and I'd say if you're just going to have one "party" game for now, Wario Ware: SM is a solid choice.