http://www.escapistmagazine.com/articles/view/editorials/zeropunctuation/2655-Yahtzee-Visits-Valve-a-Travelogue
Left 4 Dead - leaving aside the horrible practice of replacing words with numbers - is a co-op multiplayer game in which four players form a rag-tag group of desperate survivors in the midst of a ruined post-apocalyptic world where a bunch of high-speed marathon runners have somehow acquired a lust for human flesh. Together the last four humans must make their way inch-by-inch to an extraction point while fending off nightmare monsters and making the occasional traumatic decision between running back to fetch a fallen comrade or accepting that whatever shredded remains that could be salvaged from the hordes probably wouldn't be much use in future gunfights.