This is Journey, a downloadable game for the PlayStation 3 that is coming out this fall and looks like a dream. The game's creators at ThatGameCompany are running a beta for the Journey now, to test its quiet, anonymous multiplayer mode.
I played through the beta. It takes about a half-hour to get to the end of the beta's three levels, though they lingered much longer in my mind. If you want nothing spoiled about this game, don't watch. If you want a few glimpses—if you want to see beauty—settle in. I won't try to explain what's happening. You can figure it out, as I did. The discovery is the delight.