The "update files only" are made for windows. I have no Mac to test if they work there as well, but I assume they don't.
All versions of the most recent update are available here on itch, including the Mac version.
Perhaps it's necessary to open the Game.app of the old version, and copy the save files from the Game.app\Contents\Resources\app.nw\save folder into the same folder of the new game version.