"In Journey," explains Chen, "we want to offer the player the choice between individualism and group conformity... We wanted to create an environment where the cooperation is not forced; you're totally fine doing it yourself. If you choose to cooperate, then that is the real essence of connecting two players."
via gamasutra.com
I remember reading (unfortunately I forget the source), that one of the problems with graphical video games is that while you can tell when someone is close enough to shoot, you can't tell if they need a hug. While I doubt Journey does the latter either, it seems to have come closer than any other graphical video game out there.
(I say graphical video game, because in MUDs/MOOs/MUSHES/what have you, you can tell, about the hug bit.)