Wow. Really impressive for a game jam! Short but in my opinion for a game jam that is a plus. You very quickly and clearly make the concept apparent instead of getting lost in a build up.
Art style is A plus as well, and as other have mentioned the "juice" is great. I actually like the palette personally, but I can see why others say to increase the contrast. Maybe some color options would help, so people could decide for themselves the look, kind of like in Downwell.
Usually I try to give at least some constructive criticism but I don't really have any. Just wanna see more.