There's not much to tell, really. If I launch the Steam app on my Mac and search for Ravager, it's greyed out with the little 'Not Available' symbol next to it. Hovering over that symbol gives the tooltip 'Your current MacOS version is unable to run 32-bit games.' Maybe I can override this and install it anyway, but if so, the message is pretty misleading. I'd put it down to a Steam issue rather than yourselves. This happens a lot.