Wow, this is really good!
I was unable finish it, I just couldn't work out exactly what to do in the room with the spike cubes and the jelly fish. I was trying to wall climb between them, but the spike hitboxes seemed to overlap the wall slightly, making it really hard.
The jelly fish climb before that was super fun, if frustrating to fall a few times!
I think you definitely nailed not having powerups too, the level design introduced the mechanics and the ways they could be used together in a way that made it feel like you were getting powerups, even though you had all the tools at the beginning, great work!