So I just downloadded the current Mac versions, and it wouldn't unzip when double-clicked in the Finder. I used a third-party app called The Unarchiver and that unzipped the downloaded file fine. I think perhaps whatever utility was used to zip the game for Itch did something a little non-standard and MacOS's built-in zip tool couldn't understand the file. If this is the problem you're having, try using The Unarchiver ( https://macpaw.com/the-unarchiver ). It's free, well-known, and also available from the App Store if you prefer getting your apps that way.