Great idea with a terrible outcome. Limited songs in general and have fun getting the ones you want even if you are spending money. But the main issue is the controls in general, if you miss 1 note you have to pay to continue which is kinda fun until it says failed to tap when you know you definitely did but your screen just (didn't pick up on it so you spend 8 crystals to continue the song) also developers make it so you can lower the "perfect " bar that would fix 90% of your problems.