I played the version that had the original's campaigns included which means this technically counts as a review for both but I do understand the strategies differ in the first. I'd heard a little bit about this game and was skeptical when buying it but little did I know I'd be getting into one of the best PvE games of all time. It's very simple in concept but manages to have enough diversity in weapons and need for resource management. This calls for a lot of strategy in some parts of the maps which makes the gameplay loop very engaging. My word are there some unlucky moments which can screw you over but it adds to the experience. Also L4D 1 > 2 in terms of cast.