A nice start. I like the premise and the limited-palette aesthetic. Obviously seems unfinished, so not much to do other than fall off the map '^_^
Of what you got, though, I will say that I think the the first jump is needlessly extreme. I would save that kind of jump for further in the game and give the player an opportunity try similar jump without danger of getting hurt before having them do it "for reals".
Edit: I only played the web version. I see in other comments that there may be a difference between it and the downloadable.