That was great :)
Anyone playing on OSX Big Sur should know that it does work. You just need to:
1) Put the .app file into Applications (otherwise it will eventually say 'Unable to find game!' after steps 2 and 3)
2) In Applications, Right Click on the .app and go to open, which will give you a message saying it can't open it because it can't be checked for malicious software. Just click OK.
3) Right Click and go to open again, which will give you the same message as before but this time with the option to Open. Click that and the game will launch, provided it's in the Applications folder.