The game and leveldesign is fun. There are, however, some things I noticed.
For one, the jumping feels weird. When hitting the head at a platform, the player does not directly fall down. It feels like the jumping arc gets completed, which leads to delay between hitting the platform above and falling down. Another thing I noticed was that sometimes the player can get stuck in weird places (see image). This can be resolved by walking left/right, but it still is annoying.
The animations are played constantly. I suggest pausing them when the player does not move.
Since this is a platformer, I always suggest looking at this game if you haven't yet: https://gmtk.itch.io/platformer-toolkit
It explains the basics of character control in platformer games.
All on all, keep up the good work and never stop learning something new!