Hello. We are sorry you have troubles playing the game on Mac. Is seems the problem is related to the fact that GOG Galaxy is putting a few additional files in the game installation folder (perhaps to manage update and launch of the game). Since our games are signed and notarized, any modification of the installation folder invalidates the app. By default, macOS prevents running of invalid apps.

As a temporary solution, you can override default macOS security settings:
1. Choose Apple menu > System Settings, then click Privacy and Security in the sidebar.
2. Scroll down to the Security section and find the link to "Hero of the Kingdom" app. (this will be available for about a hour after macOS prevents you from running the game).
3. Click "Open anyway", and verify your identity which will override the macOS blocking of the app. The game will be launched. macOS will remember this override.