Fun game in the tradition of arcade classics. I like having to rebuild the ship after dying. It's a nice interlude between the fast action segments.
I love the core game loop and the aesthetic. The controls took a bit of getting used to, but aren't bad.
I critique the things I love, so don't take any of this as negative. It shows that I love your game...
For game feel, a few audio effects in the gameplay would go a long way.
For difficulty, maybe a progressive difficulty curve, with enemies firing more slowly at first, then more and more as you progress.
For my personal taste, I'd like the sides to wrap instead of bounce, more like asteroids.
It's a bit punishing to make the player rebuild their ship at the end, only to hit them with game-over after.
Overall, fantastic game, with a nice variety of enemies and a loving nod to arcade classics.