The sprites and soundtrack are nice, but there are a lot of issues with the game (in my opinion).
During the game itself, there was no indication of scoring. I didn't see any reason for the difficulty markers other than that - difficulty. It would be nice to have some sort of score during the game, so if you do better or worse, you know.
That way, your score is additive, instead of finding out at the end.
The combo system seems to no real function, and is a -pardon my french- pain in the ass and straight up broken. It's much easier and more efficient to just hit the notes as they come, instead of hitting space to not use them (which I only found out I could do through guesswork) and hit combos. Which sometimes, the game doesn't even register a hit.
e.g. I'd hit a down arrow, and the down arrow wouldn't light up on the combo list under the enemy.
It's a fun game, but it has a lot of issues.