cute little game. My high-score is 7213.
the shooting cooldown is low enough that you can infinitely stall or even rise up, and the camera is struggling at negative depth. Maybe weaken firing, add a falling ceiling or just an easter egg?
Music is inconsistent (intro is a cool c64 chiptune, hub is one style and the actual game is another), doesn't loop well.
The waves don't have a timer so there's nothing to discourage just running away infinitely.
Laser's cooldown makes it useless.
joystick support is very incomplete, should at least be able to do joystick + mouse.