Quite a bit!
The current page count is 170 pages, with all the book sections in but not fully detailed yet.
The core system is "playable" right now. However, mechanically the Professions are still in development. Only 2 of the 34 have enough abilities to truly play.
Alpha testing was going to be in March, but there are too many things still being actively developed to do that. I'd rather wait until the bulk of the game is stable before doing playtesting.
With the lore for the Setting and Artbook and any of its Stretch Goals already written, I expect to be doing a Patreon Alpha test for the Corebook by Late Summer.