I think Philip. K. Dick, if he were to approve of computer games, would probably approve of Half-Life 2.
"Kipple is useless objects, like junk mail or match folders after you use the last match or gum wrappers or yesterday's homeopape. When nobody's around, kipple reproduces itself. For instance, if you go to bed leaving any kipple around your apartment, when you wake up the next morning there's twice as much of it. It always gets more and more."
After all, in what other game can you beat people to death with useless junk?
Eventually everything within the building would merge, would be faceless and identical, mere pudding-like kipple piled to the ceiling of each apartment. And, after that, the uncared-for building itself would settle into shapelessness, buried under the ubiquity of the dust.