This is a really neat idea, and I really enjoy the art! I wish I could have gotten a bit further, but even as a person who loves rhythm games, I could not seem to really "get" this one.
- The audio seemed like it was popping a bit, and it seemed to start getting off-beat from the song sometimes. Even once I had memorized the pattern, it was clear that things were getting out of sync.
- You have a pretty generous timing window it seems, but it's very unclear where the actual "beat" that a "perfect" timing would be at. Is it immediately when it shows the "highlight" on the arrow? I think an actual scrolling DDR-like UI would have been much better here to properly communicate the actual beat it wants you to hit at.
Besides these, I really enjoy these rhythm + something else types of games. This could be very cool with a bit more refinement!