Nice work, this is a fun game and it seems like it was an interesting project to work on. I haven't played a lot of bullet hell styles games so it was fun to try it out but my skills are limited. I have some thoughts about the gameplay if you continue to work on it that may be obvious or things you haven't gotten to yet, but I'll put them down, hopefully its helpful.
It would be helpful to have instructions in the game, players might not notice them on the itch page before starting game in full screen.
It seems like some enemies and bullets are not getting removed from the screen, so they are still visible but not moving, and don't interact with the player.
The bomb functionality is a little confusing, it seems like the enemies disappear and then reappear but on the same trajectory, so it seems like it's actual creating a disadvantage for the player.
When you lose a life, the current wave of enemies is still there when you respawn, so you often just get immediately killed again but the same enemies, it seems like it would be easier if the screen was cleared at least of the current wave so you have a chance to recover.
A way to reset the game without refreshing the window would be helpful.
On my browser, the game window is sort of pinned to the bottom left corner, not sure if this is intentional, but it seems like an unusual positioning.