Yeah, when downloading the file all that exists is an .exe version of the game. So that means the game can only run on windows. You have to build 2 different version for Mac, and Linux (in Unity that is). Hope this helps and good luck!
Yup so it seems I'm just dumb and didn't see the Windows/Linux dropdown... I uploaded a Linux version, tell me if everything's good on your side! :)
Yep everything works! Nice work!