Thanks for the feedback, and you’re absolutely right about them.
The respawn timer is tied to when they are spawned, not when they are destroyed. I didn’t want to rework the code for fear of introducing bugs, but I could have solved it simply by greatly increasing the respawn time.
The lack of music also made everything feel a bit empty, when a bullet hell really needs that kind of full soundscape. There are the effects from the shots themselves, but not from the enemies.