Hello though fellow Godot developer! I've tried out your demo. I like the art style, and music, but I think it still has a ways to go.
First of all is the pacing. The character moves very slowly. Unfortunately, most people will be turned off by this and not play your game if it's too slow... You should make sure the player can move more quickly, or maybe have a run button. You should be able to adjust the playback speed on the animationPlayer to help your animations sync to the movement better - unless you want to rework them all manually.
I did notice the camera kept clipping through the wall. I know there is a tutorial out there on YouTube by garbaj where he explains how to prevent this using ray casts. I think it was something about 3rd person cameras.
The game performance also seems to be running a little slow. Make sure you are static typing your variables and functions - it seriously helps with performance - especially if you are planning to sell this commercially.
But I think your game looks promising :) I really love the art style. Best of luck to you, and wish you the best on your endeavors.
Btw, do you think you could give me some feedback on my game? It's a puzzle platformer called Gravity Whipped. I have been working on this game for almost 3 years and would love to get some feedback on the demo.
Thank you.