I don't own a Mac but here is some advice I've seen that's worked
"If you open this on a mac and just get a black screen, try right-clicking -> show package contents -> contents -> MacOS and click 'nwjs' and run that. I think it uses a little more processing power than running it the usual way.
If it says permission is denied to open it, try opening the terminal and putting "chmod -R a+x" then leave a space and drag the game icon into terminal, then hit enter. This works for any game that permission is denied for. Disclaimer: I have no idea why this works but it does."
good luck