Hello! On Mac try downloading the official itch.io app for mac, and then try downloading this game from the app!
Unfortunately, I do not have any other fixes for mac. It seems it works for some but not others. Apple is very stinky when it comes to app support coming from other systems. I do not own a mac, so I borrowed one to make the mac download specifically to help mac users. I am always looking for more solutions and if I find them I will absolutely update the downloads and inform you :)