This. Is. Insane. I've never really enjoyed rhythm games so I can confidently say that if more of them were like this, I would be way more inclined to play them! The artwork is ADORABLE! Harold is ADORABLE! The music is AWESOME! I can't praise this game enough for its quality and polish. Insane that this was done in 4 days.
If I had to give something for feedback, I'd love a reminder of the beat written or symbolised somewhere on the level UI. Other than that, though, perfect entry.