Hi, so sorry for getting back to you late on this one. There is a problem with RPGMaker games and newer Macs: https://www.rpgmakerweb.com/blog/regarding-future-rpg-maker-mv-macos-support
https://forums.rpgmakerweb.com/index.php?threads/need-some-help-cannot-open-a-ga...
Some solutions are using a Windows emulator (Wine Bottler?)
You can also try giving the game permissions, which should help it work.
Also, you can try to use "The Unarchiver" app from the Mac App Store. The default option to unpack the .zip of some mac system changes some file types automatically for whatever reason, and can cause such problems.
This may also help: https://superuser.com/questions/1345755/how-to-fix-the-application-cant-be-opene...
Hope it helps!