I win !
It's funny that small bullets only damage your shield but don't kill you (obviously as is the game would be impossible if they did), that's unusual. I like that you included asteroids as they add to the tension but also allow the game to feel less rigid and static despite all these not animated ships which stay in place and overall tend to do always do the same thing. I was not completely sure whether bonuses come with a drawback, I think they do, or if the ship simply shot faster sometimes which would be fine too anyway. The hp of the ships is on point and the difficulty of the game is fine as you need to be really careful during the shieldless phases and the asteroids create real tension as already mention.
I think just allowing autofire is fine (I actually like autofire but mashing the button goes as fast as you mash so potentially faster than autofire).
That was a fun playthrough, thanks for sharing.