It isn't rhythm based. Lol... Just the arrows and AWESOME MUSIC makes you think that. In reality, its a deep RPG with an addicting mini-game (Tin Pin Slammer... Should be its own Game!!!). The game itself makes you think about society.

If you want a gist of it... You play a kid, that gets transported to an Alternate version of Shibuya for some reason (you learn later). A bunch of crazy monsters called noise attack you then some girl teams up with you to fight them. You collect a bunch of pins, that allow you attack and effect these noise. The pins utilize the different uses of the DS. Like say, a scratch, a tap, a blow on the mic. It gets pretty crazy when you do the combos and try to stay on track. The other player (the girl for a while) uses the arrow keys to match up symbols while attacking. If you get a bunch of correct symbols, you can perform massive attacks that do extreme damage while healing yourself. It gets crazy when stuff backfires and you level up pins and find your perfect combinations...

then you find out you suck at the game...

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*moonwalk*? damn... no moonwalk yet. Until then