|So I played this at a party at a female friend's place. While wearing a muumuu. This will not be an objective review.|
Basically you hold the controller in your right hand and wave it around to match the dancing character on the screen. This seems to work reasonably well, and the better dancers or the people who had played the game before and memorized the arm moves had a clear edge. It is fun in a goofy way and if you're really trying to follow the dancer's moves, it gets your blood pumping a bit since they're all--as far as I saw--pretty up-beat pop or funk or hip-hop type songs, and reasonably well-known ones at that (and the original versions rather than re-creations, I think).
We had two controllers, so we could do two people in a battle to dance the most accurately, or could do a "duet" mode where basically the two may once in a while have to do-si-do around each other.
I briefly saw another mode (there were two or three others I didn't see, I think) where sometimes one players is told to do a specific move not being made by the on-screen dancer, and they get extra points for completing it.
The graphics have a techno pop glam flat-shaded style that works pretty well, and the dancing characters, done in that style, look good, although they seem to range randomly from cute girls to hip-hopsters to *fabulous* dudes to astronauts (wth) to some kind of Tron guys.
In the main mode at least, once in a while a move is tagged as a "Gold" move, and matching it correctly is worth lots of points. I never really saw these as they came up because I was too busy watching the dancing character and trying to keep up with whatever they were throwing. Icons of the next move also scoot in along the bottom, but again there was no way I was going to be able to watch them and the dancer performing the move you had to be doing right at that moment at the same time.
The owner was really into it, and we all had a pretty good party-game style time with it. The muumuus probably helped.