Really good polish, great vibe. Music is really good and fits well with the mechanics. Tiny gripe is that it almost felt too simple. Certainly the hitting mechanic needs dialing in, it's very forgiving at the moment. There's no score display, so you're just playing out the track. So there's no feedback to how well you're doing.
There could be a lot of fun adding a second timer. The track has its duration, but the second timer is counting down 10 seconds. You add time to the second timer by scoring points, if you run out of time you lose the run and have to start the track over. That makes it so that you're not playing a whole 3:30 without knowing how you're doing and if you're doing bad you fail, that way there's jeopardy to play and you get two count downs on the theme.
The above shows that there's a lot of potential here. So it shows a lot of promise, if work is carried on.
Visuals are a great fit. I think this would make a great mobile game! Well done!