itch.io

Try using the downloadable itch.io app. I downloaded the game through there, and it launched just fine for me. 

You can find the itch.io app by searching up "itch.io app" and following the instructions on their website.

Here's how you do it:
Go into the terminal app and type this in [chmod -R 777]

Then enter space, drag and drop the app into terminal (that will automatically find it's path) and press enter

If if still doesn't work or it says something about the file being damaged you can do [xattr -cr], space, and drag the app to terminal and enter. 

Hope this helps!