Hiya, I just brought the game for MAC but it's not opening when I click the app?
Howdy! On Steam it says that if you have any version after macOS 10.14 it will not run. This happens because Apple no longer makes updates compatible with 32-bit games.
You have two options now
consider downloading macOS 10.14 on a separate APFS volume (I have no clue what this means but Steam recommends it)
Get Windows on your Mac.
I'm sorry that this happened to you. The creators should have mentioned it on the store page. :<