This isn't the kind of zombie-strategy based game i was expecting for... it's... just generic.
I may be an obtuse to ask some things, like:
"Why there are few characters to control in this game?"
Well, a zombie pandemic is a zombie pandemic, everyone turns mad, making others mad as well, and... well, things goes on.
"Why, having already few units to control, they can carry only 4-5 things?"
Like everyone says in emergency cases, don't brought with you everything, even stuff you know may be pretty useless.
"Why a single map can be very long, and, probably, you will broke it, rendering your attempts to end in vain?"
That's a good question, for the not obtuse people. Really, it isn't sarcastic, i think i just broke a level in the third mission, discovered that nearly at the end of the map, and now i should play it from the start, because i can't complete it. But that should be just my problem, nothing to do with you others.
Let's say, this game is boring, because it's a predictable game, the zombies come, you run, you kill them in the way while keeping at a distance, then you run again, and so on... Or maybe it's just me that i find tactical zombie games like that. But anyway, for me seems also pretty buggy, as far as i played.
Also to note, the Multiplayer Co-op it's HORRIBLE: first you need to do a port forward in your router if you're using one to access the internet, then you can play the levels that, in case you are the host, you have completed, with the same items you had before starting. And to have from more than 2 players, you need to have completed some of the first long-levels already, because the characters are pretty few, like i said. And, after these little problems, the play of the Multiplayer.
There aren't the dialogue of the characters in the map, to understand some parts of the storyline in the game.
Your friends, that entered in your game, may be experiencing lots of lag, for some strange reason, in casual moments, without an apparent reason, even if they have a good computer. And that will make it unplayable until they will left it.
This game is poorly cared by the developers, and, i might be too harsh about this, maybe because, i repeat, this kind of games are boring for me, and maybe i am not that kind of strategist, fighting against some slow creatures... but this game, is pretty bad, and not worth it's cost.