It's funny how similar and different our games are at the same time! Same kind of aesthetic and rhythm shooting idea but completely different vibes. Very impressive outcome as a solo dev and under 24 hours!
The basic came loop works well! It was slightly annoying that shots outside of the beat window do not come out. As the beat window is quite tight, I would have hoped that maybe shots would just come out weaker if the player does not keep to the beat. I also understand why you added the metronome but I don't think it should be needed if the beat can be felt well enough in the song itself. But these are just nitpicks and probably would have been ironed out if you had more time.
Overall, a solid entry!