Now this is what a rhythm game should be!
The most striking thing about this game is its amazing selection of music. It has 90+ songs, and of the ones I've played so far (quite a lot), I have yet to find a song that I did not like at all. This is very, very good compared with, say, the US release of Beatmania, with 50ish songs and only a handful that I would want to play more than once.
There's also a lot of modes and unlockables, and plus the fact that the game itself has a rather steep learning curve for new players, this game will keep you entertained for a long, long time.
The only slight complaint that I have is the fact that there are no previews of songs. With so many songs available, sometimes it can be hard to keep track of which is which. But oh well the option was taken away 4 or 5 games ago in the series, so nothing I can really do about that.
The moral of the story, for games like DDR and Beatmania, always import them if possible, because they really ARE much better than the American releases. Dunno, guess the Japanese are much better at choosing the appropriate music for the game or something.