Well done. I like it.
Jumping was bit float'y, but it did the job.
Low hanging fruit would be changing viewport setting with nearest filtering, and others for pixel art game.
Regarding theme, I see where you were getting at, it might fall short due to visual implementation as you could see the light orbs anyway. but with some work i could have been more fitting. I can understand that it is quite hard to work with lights in Godot 4 ATM.
Keep it up!