Cute little game! Like others have said, the movement seemed slow at first but I think that's just a bit of bias from having played lots of platformers - after a while, you get into the slowness and it does suit the game's vibe. I think there were a few areas where I was able to move through the wall (or at least I thought it was a wall because it was red). I wasn't sure if this was a secret area or a glitch.
The graphics were very cute and retro - I love the protagonist. I appreciate the amount of polish in the mechanics too, eg. falling from greater heights changed the landing and added dust.
Great work :)