Really well put together game, congrats on your first entry!
I'm not that good at delicate platformers so I struggled probably more than most. My only thought would be the surface feels a little slippery and sometimes I would over-correct my movement. One visual thing I did notice was some vertical lines/tearing? I'm playing in Chrome on Windows. I think I've read something about GPU pixel alignment settings in Godot.. maybes it's that.
I got a little frustrated with drying, but want to see what all the deals I'm making eventuate to, so I'll come back and play more. :) And awesome work on accessibility!