It is a fascinating game, with a very deep story and challenging music. I came by it on an accident and I do not regret spending money to get all the ingame content from it because it was really worth it. The story, the music, the gameplay, everything is a masterpiece. You read the story by leveling up which you do by playing songs. There are normally 3 difficulties: Easy, Hard and Chaos, but some special songs have a difficulty called Crash or Glitch to them.