Nice platformer.
At first I didn't realize you could do more than one jump, you can mention that in the description. Then I found out and thought "ok, double jump". But turns out you have infinite jumps, but each one is weaker than previous one? Cool unique idea, and sfx pitch corresponds to jump strength, very creative.
Game looks nice, and the background scrolling gives the illusion of depth. Did you use ParallaxBackground node? If yes, you can add more layers to it to make it even better (maybe make further layers more blue and a bit smaller)
Cheers!