As it stated in description of the game:
The game is completely free, but with a tiny monthly donation at our Patreon page you can get access to the game and all the updates earlier than everybody else! In addition to this, you will also gain access the Patron-only feed, access to our Discrod server filled with spoilers, opportunity to vote for future updates, and you will give us an immense support, for which we will be eternally grateful!
So, sadly, you won't get anything by donating on itch.io.
But we really appreciate your help!