I had fun. Have you considered making the ship just autofire? Playing through I never really had a reason to stop firing, and if that's the case holding space the entire time seems redundant after a little while. I'm not to familiar with shmups so I dont know if another game has done that already but I feel like a shmup where you cant stop firing or only fire when you're moving would lead to some interesting gameplay if you designed around it. Just an idea. Good job.
Generic Space Shooter
This is my first game, a short shmup with 3 levels and a boss at the end.
Move - WASD / arrow keys
Shoot - space / L mouse
Pause - P
Space Ship Cronstruction Kit by Skorpio
Space Shooter Art (and some SFX) by Kenney
Shmup Ships by surt