When you try to run it for the first time you get the classic alert for the unknown dev and that it may be a virus... You have to go to your mac's privacy and security settings -scroll way down- and there you can give it permission to run. It's basic for mac but when I switched from windows to that... inconvenient... mechanic; well, it took me a while to get it.
+ I deleted the game and then tried to reinstall it to take a screenshot for you. Then it really could not be opened... It makes zero sence... So I extracted it a second time and ONLY the second extract works. It may take some extractions to work? Hope you get it running^^