Online - Left 4 Dead- An Autopsy. By NGai Croal.
"I want to take a closer look at last year's co-op zombie apocalypse shooter
Left 4 Dead. Valve’s attention to detail and high levels of polish are well
known, but after weeks of entertainment, I was still trying to tease apart
on a fundamental level ‘How’d they do that?’ How did Valve take two tastes
that taste great – survival horror and co-op – and make them taste great
together? Here’s what I came up with."