I opened it after it said the usual thing for apps not from apple store. Then it blackscreened and went full screen. I could still hear the youtube videos in the background. The close button didn't show up when I went to the top of the screen. I also couldn't switch apps because fullscreen hides the bar. So I tried turning off and turning on the computer, but that didn't work. So I restarted it. This is on a mac btw.
Drake in a Lake, we've tested our game on the same mac with the same macOS and we've also had an issue, which can be easily fixed. Try the following steps:
1. Start the game
2. Wait for the blackscreen
3. Press and hold CMD ⌘ button and press TAB once
4. Keep holding CMD ⌘ button
5. You'll see a list of apps running on your mac
6. Find a pop up message asking for some permissions for the game
7. Click TAB several times until the frame stops on that pop up message
8. Release CMD ⌘ button
9. Now you should see the pop up message
10. Click on YES (ALLOW) button
11. Use CMD ⌘ + TAB to get back to the game
12. If it doesn't continue right away, please, press CMD ⌘ + Q
13. When the game quits, start it once again
That should do the trick! Hope, it helps :)