The music sfx is really nice and the aesthetic aswell. It gives out a nice vibe. However, the movement felt a bit clunky. I had a lot of problems with the wall jump. Especially in 2-3 "Too many walls". In the area in the photo I couldn't jump most of the time, I just kept sliding down. It made it really frustrating.
I eventually gave up after some minutes in level 3-1 because I could almost never make the jump and when I did it was too late so I jumped into the spikes. Most of the times the character wouldn't jump when I pressed space in that level.
Some times when I am wide and press the up arrow I jump sometimes and sometimes nothing happens. It felt like a bug.
I liked that you introduced new features along the way and I noticed that you had some form of save system aswell. Good job! If you managed to fix the jump bug I would like to try it again :)