It is deliberately an open secret and there is no progress statement by design. One of the main goals is that the game will only release when the dev feels it is complete so effectively anything that is shown is not to be taken as official progress as he will completely rework huge sections rather than accept sunk costs and build on top of shakey foundation.
It does exist, I've seen some progress on it, but if you want to see actually be able to see the progress updates you need to be active in the discord server
You must be registered to see the links
. Although even if you are active enough to get it there's not much to see. Dev isn't restricted by making releases or living off their supporters, so the design is very much ground up. Crazy amounts of development are being put into the framework for the game so that once it's all put together adding more content will be a breeze. To my knowledge they are mostly done the framework and have begun working on the editors. If you want to see what's public content search the general chat for media uploaded by "Satyr Nate"
What I have seen posted looks really quite good, I'm sure as hell hoping to see that game one day.