rhythm game with a great style and good tunes, too bad the delay gets unbearable on top of super strict timing

I love a lot about this game but unfortunately its so broken and inconsistent that it becomes sort of frustrating. Parappa 1 has it's issues but this is another level. Also the scoring system makes 0 sense at all to me (mostly the impact and rhythm scores) I wish I could get any help in figuring it out but I can't find anything on it.