Porbably the best zombie game to date, with 4 player co-op throughout the hole campaign and a little arena DLC as well, this game is certainly worth your time.
A kind of FPS ish game mainly melee weapons though, there are firearms; indeed one character is a gun specialist, however a headshot will not kill a zombie in one...it will kill a human in one, but once a human is a zombie they become immune to headshots...obviously. WHAT THE HELL!? They almost made this game 2000 times better by having an insta kill for headshots on zombies system to it, but no...it wont happen will it? They'll never say that killing a zombie in a game can only be done via a headshot. If anyone knows of a game where it's an insta kill with a headshot please tell me about it, i'd be very interested.
Anyway the campaing is pretty long, it's like 4 or 5 chapters and a heck-load of sidequests throughout the game. RPG elements such as levelling and upgrading weapons really adds to thie feel and awesomness of this game too.
I was leant this game by a friend when they bought it, as i had no money but really wanted to play through it. They wanted it back after 2 weeks and I had gotten through 87% of the game, so I had to wait till the coming christmas and then I played it through again with 2 of my friends, which was one of the best gaming experiences of my entire life. The co-op while it can be slightly laggy is generally really cool, trading items and all that is quite simple and you can "accidentally" kill your friends..ya know if they frive off without you on a quest or something :D
So yeah I think there's another DLC out but it's campaign....didn't really look too enthralling, anyone with an opinion on that could comment....I know next to nothing about it.
So in conclusion an awesome FPS/RPG zombie game, that has co-op and an arena mode and did I mention zombies? Get it, play it, love it :D