Health problems or not, reworking the game after the first couple of releases was shady AF to begin with and the second he announced it I knew this was gonna be abandoned sooner or later. I think its just as likely he never even started a "rework" as it is him having health problems, so who is to say? but Here is a quote from the announcement post...
" I've sort of been stuck in purgatory for a while now. In development as well as in daily life and they sort of blend together making for an exhausting process."
Seems to me this game turned into more of a chore than a passion. I mean did you guys really expect an alternate outcome? I couldn't have been the only one see this coming...
Regardless of the reason... it is a sad day