This game is amazing. Not for the gameplay or design, but for the story it tells and the excellent building of tension.
I would love to see a game similar to this one. Games that are seemingly cute and innocent but turn out to be much darker are my favorite.
Sorta spoilers ahead as I would like to talk about the ending.
So, this boy decides to build a treehouse with his friends but they all died during a storm.
How I see it is that this boy never had friends at all, but pretended he did, when it was really just him and his toys. I prefer this interpretation better as I was lonely and had to play by myself as a kid, so I relate to the boy a lot. I would pretend someone else was there with me. I had fun, but the overbearing loneliness of not having friends to share it with is very emotionally scarring for a child.
Either way, great game! I loved it and I hope to see more like it.