A ton of replayability, I was in the mood for a rhythm game when this came out and I was playing it daily for a good while.

The small amount of story in this game shifted me from being wary of what Tetsuya Nomura is planning on doing with the character of Yozora and the world he comes from, to having total faith in where the series is going.

Believe it or not, with this game and the ending of the mobile game which was actually somehow good, the story of Kingdom Hearts is the most engaging it's ever been.