Yes, I know all of this. Are you saying that it wouldn't look nice on a 1800p screen? If not, then I have no idea what you're getting at.
I think it look really beautiful on a 1800p but not much difference from a 1080p screen because the size of the screen... the screen size of the Mac is small to show all the quality of a 1800p resolution.
In fact I think this demo of Rayman Legends is better than Rayman Origins because the art style... I liked it.