Some of my favorite gaming moments stem from co-op sessions with friends, and the chaos that can ensue when all your careful plans start to go awry. World War Z is a competent but basic shooter that seems designed to foster those sorts of memorable moments, and that is surely its greatest strength. It’s a good venue for a group of four friends to get together, topple massive zombie hordes, maybe save a few survivors here and there, and laugh about it when the results roll in. There’s nothing revolutionary or even that remarkable about World War Z, but the formula it follows is proven to be fun.
Comparisons between World War Z and the Left 4 Dead series are more than justified – unavoidable, even, as Valve’s decade-old series is still revered today for its fast-paced action and ability to throw dozens of raving zombies at you at once. Ever since, there’s been a certain set of guidelines one looks for when dealing with co-op zombie shooters. World War Z neatly checks every box on that list while upping the amount of zombies that can be on screen at a time considerably.
Source: IGN.com World War Z Review