Pretty fun game, really impressive for a first timer! Also very creative take on the theme ^_^
Only real problems I found were the music not looping (or maybe it stopped looping after a while? It stopped playing at the level with the green platforms) and being able to phase though the floor if you fall too quickly in the last level (As far as I know that problem is due to Godot not really having any continuous collision detection, not sure if there's a good way to fix it but I'm not really up to date in that regard so idk)
Some things that would have improved the experience for me would be controller support, some kind of speedrun timer and level select since it would be fun to try and get some good times on the levels and some textured skybox instead of just a solid color
Overall had a great time playing, GG!