The game looks beautiful and I'm definitely keeping an eye out for this one. Though, when it comes to actually formative feedback, I have a bit.
First off, I highly suggest removing fall damage. Falling in most cases here already meant getting back to the start, and in the cases it didn't I felt punished enough by having to navigate back to where I fell from. Taking damage on top of it, only served to frustrate me and 2D platformers in general rarely need the mechanic.
Second, the wall jumping was quite difficult. I understand how it works but the motions to do it can be tricky to do consistently unless I slowed down to really think each input through, which is hard to do on your tenth time jumping up the wall while trying to speed back to where you last fell. I think it would be beneficial for the game to simplify them.
And lastly, the game is in dire need of a tutorial. Figuring things out took a bit and I still don't understand everything.