How long do you wait after clicking play? There is a dark gray screen that loads before the Unity logo fades in and the game starts, that's normal. Are you seeing any errors?
About a minute - there are no errors, there's nothing to click on the screen either. I know that Macs/Apple over the years has been making 32-bit, 16-bit games, etc... unavailable to play but I'm not sure if that has anything to do with this :0