I completed this over the weekend. It took me probably only 5 or 6 hours. That is short by most game standards, but in this case, it felt appropriate. The game didn't wear out it's welcome and although I was left wanting more, There was still herd mode to spend some time on. There were 3 (maybe 4) instances in the game where you could pick between two levels (towns/locations to travel to). So another play-through would be needed to see everything.
It's an addictive game. By the end of it, you'll have become a seasoned zombie-killer ready to infiltrate zombie-filled locations like the characters in the show. The game succeeds brilliantly at achieving the right feeling. You have to watch your ass, constantly. Think you cleared out that alley you want to back into as a bunch of zombies bears down on you? You can guarantee there will be one fucker that wondered-in behind you to ruin your shit (they generate sparingly). You respect the dead. There is no room for Rambo in this game. Sure there will be moments where you have to dish it out with a shotgun. But that's only because you really have to. More than one zombie means you're probably going to want to use a gun, so you have to be smart because you learn quickly that ammo is a scarce asset (although by the end of the game, I had a few guns I never used). Some levels I pretty much didn't see half of what they have to offer because I was out of ammo and there were just too many zombies out to explore it all.
There are other aspects of the survival feel that work to some extent, but not as solidly as the actual game play. You can help people throughout the game and some you can bring along with you. They can scavenge (off camera) during the levels. Their success depends on how many survivors you assign, what weapon they prefer and their health. You'll actually welcome their help because not only can they provide extra ammo, but you'll also need gas (to travel from level to level) and food (to heal) to survive. There are mini-levels in between the primary ones where you can go scavenge yourself. These levels add a nice random encounter aspect to the game although they can repeat from time to time which does take something away.
Norman Reedus and Michael Rooker's voice acting is awesome. If you like them in the show, you'll like them here. You get some insight into how things unfolded when the zombie outbreak first hit them.
One thing that bothered me was that some doors can be opened, some not. Why not show them boarded up? And I guess I've been trained that in video games, you should be gaining levels through experience. Here there is no reward aside from staying alive, in killing the zombies. Maybe that makes it more real? I guess that's up for debate.
I'd venture to say this is one of the better zombie games out there, even though I'm probably in the minority on that one. It gets the nuances of zombie survival nearly perfect - at least as far as what TV and film has taught me. It's fun to explore the levels and find resources and collectables and it's fun to kill zombies, especially when shit hits the fan. There is a real sense of horror in it, so much so, my wife enjoyed watching me play and was hoping I'd start it again when I was done.