Definitely one of the best games I have played so far, really rewarding gameplay. That feeling I got when I jumped off the tree, and when I placed the ball in its pit, is one of the best feelings ever. I could totally continue playing a full on game like this.
On the other hand, I should mention that the game feels slow around the middle. I feel I was doing the exact same thing for a while, maybe you could shorten it or use it to introduce a new mechanic with every tree, though I understand it is hard to add many new mechanics in the timeframe of the jam so the first option would be better.
This is a small thing but I would appreciate it if the controls were explained in the game, even if by a stationary wall text at the beginning.