1. Download the game and navigate inside the folder to find Game.app
2. Choose "Get Info" from the context menu and scroll down to the Sharing and Permissions part.
3. Check that your active user (marked with (me) after the username) has Read and Write permission.
4. If it's not the case - set it yourself via the menu. After changing permissions click on the gear icon and choose the "Apply to enclosed items" option from the drop-down menu.
5. Now we are sure that your access rights are adequate and you are ready to add LoC to your applications. Do so by drag-and-droping the Game.app into your Applications directory (by default it’s displayed on the left side of the Finder.) This will require Administrator access.
6. Run League of Corruption and get inside the options right from the main menu. The first time you execute it MacOS will warn you that I am not a licensed Mac developer. Oh noes. Ignore it and run LoC.
7. Change something like a volume level in option menu and hit escape to check if the error appeared on the screen.
8. Start a new game and try to save your progress. The first opportunity to do so will be when the main character will get out from the cellar - just hold enter button to skip the dialogues. Check if you can save your progress and load afterward.
9. Great! Now you can be sure that LoC runs without any problems on your Mac.