Back last year, while rooting through the IGF entries, I found Parallax - a game that made my brain all hurty. In a good way. It describes itself as "a first-person puzzle platformer with overlapping spatial dimensions." I describe myself as "a bit scared by how complicated this looks."
"Weave back and forth between black and white," they say, "as you try to be in the right place, in the right dimension, at the right time." I'm incredibly poor at being in the right place at the right time with this one dimension. Just look at it!
It looks a bit brilliant, right? And so damned pretty. It's currently in the cockfight for Steam Greenlight attention, when of course Valve should just be doing their job and asking for it to be on Steam themselves.