Nice game! I like the idea of locking the camera to the player, which helps to avoid some of the confusion that sometimes comes with rotational keyboard controls. The game is slow to start, but gets sufficiently challenging over time for sure.
One thing that I think would make the experience even better would be to have a more even aspect ratio, or at least have the spaceship aim along the longer axis. I saw some enemies, only to have them go out of sight when I rotate the view to take aim.