Sorry that you are having trouble with this! We will check it out tomorrow when we're back in the office and see if there's an issue with the itch.io build.
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".
Have you been able to get the app notarized properly, or do you still plan to? I bought the game last night, tried to open it just now, and am still getting an error message saying the app can't be opened because the developer isn't "known". Any chance this issue may eventually be resolved?