You may enjoy https://apple.stackexchange.com/questions/414688/how-can-i-run-newer-unity-games-on-os-x-10-9-mavericks https://apple.stackexchange.com/questions/

You may enjoy https://apple.stackexchange.com/questions/414688/how-can-i-run-newer-unity-games-on-os-x-10-9-mavericks https://apple.stackexchange.com/questions/414688/how-can-i-r..., in which I figured out what was keeping modern Unity games from working on a very outdated operating system, and got them to run. I'm really quite proud of the writeup! :)