I just love the fact that this guy shares everything on those forums.
I remember seeing early parts of his work on papers please and there is something wonderful about sharing your process and exposing it to feedback.
Tigsource is a treasure trove of information and design docs. Lots of famous games were hatched there (spelunky and dead cells to name a few).
I feel like you have to have an audience of sorts while you work, else it's like screaming into the void.