I really enjoyed this! Great art, sound and music, and the controls felt perfect at least on a gamepad.
I just missed the lack of full screen and a pause menu (got food delivered in the middle of the boss fight :P ).
Some little glitch I noticed is that the motion trail seems to have it's initial postiion set to 0,0 or maybe it gets that value when the enemy scene is added to the level. Thing is you can see it swipe across the screen from a few frame when enemies are spawned far to the right.
Congrats for the great work!