This is one of the most innovative and fun games I have played.  I mean, it's just good is all.  It's sort of like Parrapa the Rapper, in that there are sequences of moves that you have to do.  The difference is that it's dancing instead of rapping, and there are a lot more complex manuevars.
    The games works like this.  A set of direction keys appears on the screen.  You have to push those directions within the first three beats.  On the fourth beat, you have to press either the O or X key.  The more moves you do in a row, the more points you get.  You win in a sort of arbitrary manner.  Whoever the camera is more on is winning.  If the camera is totally on you, you are frickin killing the other guy.  There are also solo routines, where it is just your turn to dance.
    You don't neccessarily have to follow the button combos given on the screen.  You can mix and match to a certain degree, to make your moves more complex, and to get a higher score.  This takes remembering of the combos, and knowledge of when certain combos can and can't be used.  You can also attack your opponent with the Triangle button (twice a round), but they can dodge it with the Square button.

    The characters are really fun.  There are the main characters, and four bonus characters.  My favorites are Shorty - the girl with the kinda girly style dancing, Hiro - the Disco Guy, and Heat - the breaking, popping guy.  There are actually a few breaker, poppers, as that provides the most enjoyable visual sensation.  Of the bonus characters, Capoeira - the aliens are decent.  Columbo is Shorty's mouse is fun to use, but his moves are the same as Shorty.  Burger Dog (I like to call him Dinner Dog because of the Itchy & Scratchy friend of the same name) is alright, although he only has little stick legs and arms, which really limits the amount of stuff he can do.  His moves are the same as Hamm, but his puny limbs just can't do the job.  And finally, there is Robo-Z -the robot (duh) and the boss of the game.
    The best thing about this game is the music.  After playing this game, I could only think of this music.  Capoeira's music is good, Shorty's music is good, Kitty-N's music is good, Hiro's music is good (albeit biting "Staying Alive."  But he's a disco guy, what do you expect?), and Hamm's music is very, very, very, very, very, very good.
    Finally, the dance moves are fun to watch.  My friend got this game simply so he could learn Heat's moves.
    This is a high quality game.