As a Just Shapes & Beats player, I really liked the game! It is really fun and challenging! And it can definitively be expanded with new enemy types, new songs, etc.
It would be really cool if the player had to destroy the enemy that follows them, by automatically shooting on beat, for example. Because it has the "problem" as Geometry Dash custom bosses: You dodge attacks until the enemy randomly self destructs or gives up. But that's definitively not a problem, just a suggestion that I'd love to see!
The visuals are really nice as well! I'd also love to see some post processing on this game, like bloom. I think it would really make the game stand out!
And I really like how you made the hitboxes. I've seen a comment that complains about the hitboxes, but I disagree with that. I could understand how they work by myself after 5 minutes playing.
Overall, I really like this game, great job! Let me know if you ever update this game!