Fantastic work. The smooth controls, minimalistic graphic choice, and soundtrack all contribute to a very immersive gamefeel. The concept is well executed with fun levels, and the hold-jump mechanic is satisfying to use. The only things I'd like to see are a level select screen, and a win animation instead of an abrupt stop which takes out of the immersion a little bit. I can see a lot of potential in the game, both in the puzzle direction and in the platformer direction utilizing the hold-jump mechanic to smoothly sail across landscapes. Great job!