I cannot expand the macos archive. I've ried moving the archive, using extraction softwares, used Terminal to unzip. I either get a Mac error -1 (operation prohibited) or "You cannot open this file because it is damaged or incomplete.)

Help?

OK... after a few hours of framping about, I discovered that if you go to  itch.io and find your inventory, there is a download opportunity linked to the game... and it works!