The art that's there looks really, really cool, especially the background art. The dialog after the miniboss got a chuckle from me. Since you specifically asked for feedback on controls, I'll give you my two cents in that regard.
- Movement: Seems fine, feels responsive and the speed was good.
- Jumping: You've got variable height jumping in and that works great. The two things that stick out to me right now are 1) no coyote time (being able to jump if you press the button a few moments after moving off of a ledge) and floatiness. A lot of games will increase player fall speed (or gravity's influence) to make a jump feel snappier on the way down, you may want to experiment with this. I don't know if Godot has this function, but leaving a line trail behind your character while testing will allow you to more easily visualize the arc and feel of your jump.
- Dashing: I would think about how the camera interacts with the dash a bit. Right now the camera remains behind for a really long time and then snaps to the player very quickly which givs the dash a bit of a whiplash effect. Also, even without proper animations, just rotating the character sprite a bit can make a world of difference for a dash's presentation.
- Attack: Seems it wasn't fully implemented, but even as is its behavior was inconsistent. Sometimes my weapon would just move downwards very slowly, and sometimes it would move forward very slowly, I was never sure if it was reacting to my directional inputs or was just inconsistent.
Anyway, those are my thoughts. I really enjoyed the art style, and hope you can overcome whatever was holding you back and continue working on it!