Really the biggest con going for World War Z is how hard they tried to make it an obvious Left 4 Dead clone without trying to be its own original thing. Anyone who has played L4D before is going to instantly recognize a lot of things that were clearly adopted for this game. It honestly reminds me of very similar situation years back with Dante's Inferno and God of War. Dante's Inferno was a solid game but such a blatant rip-off that it left a sour taste in the mouths of many. I feel the same applies to World War Z.
Aside from character classes, minor customization options and improved graphics, There is very little difference between the two games. I mean heck, Even the undead have virtually the same special characters (tanks, smokers, spitters). The developer couldn't even be bothered to create their own, they just flat out took what L4D already offered and put it in the game. It was almost laughable to see but at the same time, it was so disappointing.
Now don't get me wrong, World War Z is still very much a fine game to play. It's a simple shooter that knows it's a simple shooter. The controls are satisfying and it's a blast slaying waves of the undead. However, The limited content options and poor matchmaking sessions left a lot more to be desired for me. I could honestly play a level or two solo before someone joins the match and even then, they aren't guaranteed to stay. So what's the point in offering online co-op if it is such a hassle to play?
And the game only offers 4 chapters which are made up a various amount of repetitive missions each (14 missions total). Each follows the same template: Walk, have a few minor enemy confrontations, Do some objectives, Face a small horde, Do more objectives, Face a big horde and then end the level. It's very straightforward and kind of boring after a while. There's very little story and pretty much no replay value to it either. So don't expect a lot of depth in this aspect of the game.
There is a PVP online mode but honestly, It isn't even worth checking out. As I mentioned above, You'll spend more time waiting for a match to start than actually playing one. I wish they just did away with this aspect of the game and focused more on adding something more creative and unique to separate it from the game that clearly "inspired" it.
Overall: 4/10
It's a somewhat fun clone of L4D but it is a clone nonetheless. A clone with very little content and virtually no replay value. If you want to rip off a game, especially a popular one, maybe try not to be so obvious about it next time.