After spending a few too many minutes playing "Combine" on Facebook, I turned back to the rest of my computer desktop, and got the very strange feeling that everything was more square than it should be. Combine just seemed to have the right size and amount of "roundness" to desensetise my eyes to it, expecting to see it everywhere, so suddenly the squareness and sharp edges of everything else look over-exaggerated.
Mokalus of Borg
PS - I think the game itself is rather good.
PPS - I'll need more practice to get good at it, though.