What do you mean by private development?
at a certain point, the project will be so large that a monthly release schedule isn't practical. we'll use what we've saved from our patreon campaign to fund a private development to push us towards a finished state. the last monthly version of the game will become public and free forever, and the full game will be developed in private until it's ready to be released in full (at which point it will cost money to own a complete copy).