One is sandbox working right now, and two how does the game download, the network I live on right now does not allow for peer to peer downloading.
Two questions befor i buy
There's a sandbox mode in the beta
You can download either from the itch.io site directly which is basically just a zip file over HTTP. You just uncompress the zip and run the exe to play the game.
Or by using the itch.io client, which I believe also uses HTTP as well. The client doesn't use P2P to do its downloads as far as I can tell