1) The pacing is all wrong. It starts off really fast, with at least one excellent jump. The fear and confusion that the characters are feeling is palpable. Unfortunately from that point it gradually slows down, until the end is much closer to a 1970's type of film, with characters trying to creep around so the Zombie's don't hear them. By then I just found that pace frustrating.
2)There's a real lack of character development. You barely learn the names of any of the people Brad Pitt's "Gerry" meets as he whizzes around the globe, let alone enough to give a shit when they die, even if they are nobly sacrificing themselves.
3) The film is rated 15 in the UK, which is a better than a 12A, but not as good as an 18. This is a Zombie film. I want gore! There's barely even any blood, and although the Zombie's bite people, that is very clearly part of the virus spreading itself and they never seem to eat anybody. I watched Dark Shadows last night (so much better than the trailer made it look) which is a 12A, and that had more blood in it than World War Z. Mental. I wonder whether the censors were being hyper-sensitive because of the presence of Zombies and actually cutting more than they would in something based on a Gothic soap-opera?
4)I love the book, and I'm assuming the people behind the film love the book, because otherwise, why would they adapt it? However, the film comes across as having been made by someone who has been told about the book by someone with a bit of a dodgy memory. It's almost like, every now and then, they think, "Shit, we really ought to reference the book," and then put in something really clunky that interrupts the flow of the story.
So, that's the bad, now for the good. The beginning is good, really exciting and draws you right into the chaos and fear. Brad Pitt is good and really likeable in the role. I found myself thinking what a good dad he must be, because he takes really good care of people. The acting of the Zombies is good. There are lots of moments that are visually spectacular and I was glad that I saw it on the beauty that is Screen One of the Empire Leicester Square (my second home). I was so excited when I heard they were doing this film, and when I realised how different from the book it was going to be I made a real effort to down-grade my excitement, but I still felt a bit let down. If they'd made a film called Brad Pitt versus The Zombie Hoards, it would have been amazing, really fun, and not messed around with one of the best Zombie books ever written.
My final plea to anyone who's listening is to please not make any sequels, but for HBO, Netflix, or the BBC to get Max Brooks on-board and make a mini-series. Get George Romero to direct an episode and Greg Nicotero to do the special effects. It would be the best thing ever.