Cute first game! As Ellie said sfx would improve the feel a lot more.
Also, I felt some of the jumps (where the "floor" is near the top, like the image below) were kinda tricky to do since you have to walljump from an exact spot or otherwise the top will block he player's jump, after a few tries I found this to be kind of frustating. Still, walljumping is a pretty good and fun idea.
Pretty good game, congrats!