Really cool game ! Here are some suggestions (In order of importance according to me):
1. Add some sort of warning at the position where an enemy is going to spawn, it will make it easier to get away from them and not accidentally run into one when moving away from another.
2. Add more feedback for when the player is hit, right now the screenshake is just not enough imo (Maybe add something like a red overlay to the screen?)
3. Add more juice to the enemy death (Purely aesthetic, but it will improve the overall quality of the game)
4. There is also an option to imbed the .pck file in the .exe in Godot, using this is probably a good idea.
Good luck !
P.S What does the Confusion effect do ?