This is a common issue for mac, heres a great tutorial that helped me
Solution - "app cannot be opened" error
1 year ago(-4)
No one on the development team has a mac to test the game on. I make a build for the mac and just assumed it would work the same as on PC
its cause theres no script set up for the terminal to read.
1. If you go into the apps content folder you'll see nothing for terminal to actually read.
2. You'll have to change all the correct files using the chmod +x command and the file itself in terminal
3. even after all that...it still wont run, I know cause i call out the team for this if you directly to the update link.
4. the only other reason it can't run is:
a. Bad coding or
b. its running on 32 bit and if you have the newest OS, it wot run any app that is 32 bit