Mechanically, this is very interesting. There's still so many directions you could take the water pressure mechanic, that I'm having a hard time not putting on my designer hat and brainstorming away, haha. I also really dig the player art.
I did notice that I seemed to be able to double jump infinitely; like, I could hold the spacebar and fly. In general, a lot of the controls seemed to have some weird little quirks like this that could use some ironing out.
Overall, you've got me very intrigued. I want more of the water pressure mechanic, and I also want more of the world you've built. While you don't get much of it in this demo, the description on the game page has really got me hooked! Looking forward to seeing where you take this if you have plans of continuing development.