Zombie cinema has come an awful long way from the no-budget claustrophobia of Night Of The Living Dead to this globe-trotting action horror that’s as epic in scale as it is in expense.

Once regarded as little more than a niche genre presided over by George A Romero, the zombie flick was reanimated for modern audiences by Danny Boyle in his 2002 horror classic 28 Days Later and since then has lurched its way into the mainstream, to the extent that even TV has embraced it in the form of the hugely popular cable show The Walking Dead, based on the comic book of the same name.

While the undead were doing their thing on the big screen, Max Brooks’ 2006 novel World War Z took a wholly new and plausible approach by presenting itself as an oral history of a 10-year global zombie war; a collection of personal accounts compiled by a United Nations agent examining the various geo-political, religious and environmental changes that occurred as a result.

Adapting a book with World War Z‘s particular structure was always going to be tough, but it’s nevertheless surprising just how fast and loose the filmmakers have played with the source material, to the extent that virtually the only thing connecting the two is the title.

The novel’s only common thread is its narrator, so it makes sense the driving force for the movie is former UN investigator Gerry Lane (Brad Pitt), who’s portrayed as a loving father to two girls and husband to Karin (Mireille Enos), presumably to remind both us and him what he’s fighting to save when it all goes down.

And boy does it all go down right from the first few minutes when, sitting in heavy traffic in downtown Philadelphia, they are suddenly and violently attacked by a growing horde of rabid zombies. The family barely make it to the roof of an apartment complex, where they are extracted in the nick of time by helicopter (whose complement includes a blink and you’ll miss him Matthew Fox) to a US Navy vessel, where they discover the terrifying scale of the worldwide pandemic. Told that he and his family will be forcibly evacuated off the ship unless he co-operates, Gerry reluctantly agrees to join the needle in a haystack search for Patient Zero, starting at a US military base in South Korea. From there, Gerry travels to Jerusalem and (randomly) Cardiff in a race against time to find anything to give them an advantage against “Zeke”.

A general rule of previous zombie movies has been to suggest the disturbing degree of the outbreak through emergency radio broadcasts or fuzzy television pictures. Not so World War Z, which tries to live up to its hardcore title by wallowing in the devastation, be it the military bombing the hell out of a city or an anthill of zombies furiously piling on top of each other to traverse a massive wall the Israelis have constructed to supposedly keep the undead out. Before you have chance to catch your breath, though, Gerry’s off again on his whistle stop tour.

As the film progresses, however, the focus gradually narrows from CGI-heavy mass destruction and chaos to a relatively claustrophobic third act set within a laboratory, which was bolted on after the movie’s original ending was jettisoned by the studio and producer Pitt.

Although clearly financially motivated (a static indoor location is far cheaper than horrendously expensive reshoots on the scale of the rest of the film) and somewhat derivative of many a great horror movie that’s come before, director Marc Forster makes the best of what he’s given and does a solid enough job ratcheting up the tension, although this is dampened by one unintentionally humorous zombie’s endless teeth-clicking.

While Brooks’ episodic narrative gave the reader a thorough sense of each individual and their story, World War Z’s script doesn’t have time for such distractions as character. Despite his commendable efforts to get the thing onto the big screen, Pitt feels like the wrong fit for Gerry. An actor with more range would have better suited the material and given the audience a greater sense of the personal impact this unimaginable horror must be having. And with the exception of Daniellla Kertesz’s Israeli soldier, no-one else is given the chance to make any impact.

Watching World War Z, I couldn’t help having the feeling that it would have worked better as a cable TV mini-series. The famous Battle of Yonkers chapters aside, wherein US soldiers make an Alamo-style stand against tens of thousands of ghouls (which is missing from the film anyway), Brooks’ novel largely stayed away from massive spectacle, concentrating instead on ordinary men, women and children fighting for survival.

As fast-moving as the thousands of undead who swarm across the screen, World War Z aims to be the last word in zombie-geddon, but in sacrificing character for spectacle it ends up lacking the bite of the genre’s true classics.