So I really dig the artstyle, first 3D Godot Game that I see in the jam. Really like the pixelated look that you gave it.
Other than this, execution wise the laser beam doesn't make for good combat I feel, you often get kill at the same time the enemy see you. I think you would of just been fine being able to destroy them at all time.
Laser attack are tricky, you have the wind up part and the fact that the enemy doesn't look immediately the player, but you also need the laser to extend over time to give a fair chance.
Other than the fullscreen issue, everything seem to work fine and the control are rightly introduce !