Hi! Great game! Made it to the end. I love puzzle games like this and this was a well-designed one! I thought the pixel art was great and I really appreciate the cohesive art style and UI.
I was running into the same problems other people were mentioning related to jump height. I tried it with both the Windows build and on a couple different browsers, all with the jump height too short. I had a hunch that the jump height might be tied to fps and I was correct. I was able to lower the game's fps to 30 using nvidia control panel and that allowed the jump to go higher. Funnily enough, if you make the fps too low (like 20), it makes the early jump with the spikes above impossible. I've not messed with Godot before so I'm not really sure what to suggest, but there's probably a way to make the jump time so it is fps-independent.
All that said, I liked it a lot! I think all the mechanics were fun to use and then using them in combination was also fun. I really enjoyed this game overall! Great job!