Gorgeous graphics and a lot of polish, very nice!
It's a great platformer, though I really wanted a bit more control by having an alternate keybind for jump. I used arrows and WASD combined to emulate that. As another mentioned, it did make it hard to get through smaller tunnels at time too. The depth of abilities growing each level was very nicely done, small sign and you knew what to do! I just wished the level design forced you to use those abilities a bit more to retrieve the keys.
I didn't get the background layers were the prior levels of the game, having an animation transition to the new layer to connect the doors would have been helpful to convey that. I was expecting at first that I'd be able to use the background platforms somehow ala some of the older Paper Mario games during their 2D sections 😅.