Beat the single player campaign. Steam says my total play time, with one run each of coop and single player, is 13.2 hours. And people were complaining that the game was short? The unrealistic, overly critical demands some people seem determined to put on this game, as far as I can tell as retribution to not getting free games they already owned or not getting the game earlier or something, is ridiculous. Apparently people are complaining about the "Don't turn off your console" message that's in the game, neglecting to mention that that only appears if you use the manual menu save option, which is there pretty much specifically for the benefit of people on a gamepad without a quicksave button handy, and that it was barely even visible enough for me to register the words were there when I looked at it.
IMO, this is absolutely Valve's best work yet. I fucking loved it. Might do a dev commentary run tonight, I missed some achievements so I'm definitely going to do another run (not sure which mode) tomorrow.