I really enjoyed the game for about a week - when the songs were new and I was able to progress. But it is unbelievably difficult and frustrating to get 'perfect +' on all beats in order to get diamond rank on a song. If i get only 'perfect' well perfect is perfect, this should score higher points. If you frustrate users it's going to reflect in reviews... and less purchases. I mean, why pay or even play when you can't win???