You shouldn't need a Mac. What I mean is there are some devs that don't test the Mac / Linux build, but can be launched just fine (eh well the Mac at least, not entirely sure about Linux but you can run that like another bootable OS whether as a partition or off a flash drive aka slow IO speeds) regardless if the dev even fixes those issues like replacing the internal jre folder from within the app with the Home folder (rename Home to jre) of a downloaded "Java SE Runtime Environment" or removing the extended attribute com.apple.quarantine from a "damaged" app via Terminal command. With Unity, you shouldn't have worry about this because the Unity devs are always updating the compatibility side of things and more, for instance building an Xcode project (yeah for the Mac build do not check this option) for you (they have done as much automation as possible, so regardless where you build from, cross-platform is pretty much taken care of). Especially when you get stderr / log file, it makes it closer than ever getting something to work. The only difficult part (something I never tried before) is reverse engineer a file to make it work (I'm pretty sure it's possible), like find out where the error lies and patch it yourself (through hex editing / assembly language?). I also have Unity too, so I might be able to help with translating things (trying out new things with Unity instead of figuring how to deal with multi-sided collisions through various ideas lol). I only said don't worry because I typically do this anyway (if the app doesn't work, I'll look into it, unless you want to?)