Double-clicking the app gives the error, "The application "Pupperazzi.app" can't be opened." Open a terminal window, go to the folder containing AShortHike.app, type "cd Pupperazzi.app/Contents/MacOS", then "chmod +x Pupperazzi".
I found this solution (guess that you are on Catalina, as I)
I also had trouble running the game on MacOS. Here were my workarounds.
1. Double-clicking the app gives the error, "The application "AShortHike.app" can't be opened." Open a terminal window, go to the folder containing AShortHike.app, type "cd AShortHike.app/Contents/MacOS", then "chmod +x AShortHike".
2. Double-clicking the app gives an error that the app can't be opened because MacOS can't verify the developer. Instead, two-finger click on the app, then select Open from the context menu, then Open from the warning dialog.
3. The app has garbled graphics output. Wait a few seconds for the splash screen to complete, then type Z, down arrow, enter, enter, down arrow, enter, up arrow, enter, which switches the game to windowed mode, making the options screen readable.
Mike
For me just step 1 & 2 did it all, if you want to play windowed, you can change the settings from the ingame
