If you happen to be able to read Japanese, here's all the info about the game.
http://www.konami.co.jp/am/bm2dx/
If not, allow me to explain.
beatmania IIDX is a continuation of the beatmania series by Konami. The game requires players to use keys and a turntable in corrospondence to falling bars on the screen. The game very much so resembles DDR (Dance Dance Revolution, not Double Data Rate) in that sense. However, you use your hands for beatmania. The IIDX implies the inclusion of two more keys, as the original beatmania had 5 keys (and if you can't add, that's 7 keys now.) In anywhere but Japan, the game is only playable at your nearest arcade with a machine.
Unless you're like me and can import it
...Which I did.
Now I must warn any potential players, this game is HARD. Many players give up IIDX because of its steep learning curve. It only took me a few days to pass all songs in Beginner mode, but for most it can take weeks.
Discuss.
