Thanks to a resurgence in its popularity following the box-office hits Dawn of the Dead (2004) and Shaun of the Dead (2004) earlier in this decade, the zombie film has been enjoying something of a renaissance in the past few years, culminating in the relatively low-key Zombieland topping the US box-office chart ahead of its bigger budget screen rivals. Its arrival is something of a significant one; while Shaun, and to a lesser extent Dawn, were clearly produced by die-hard fans of the genre, Zombieland’s existence appears to be largely a product of the increasing mainstream appetite for what could be happily dubbed the zom-com; in short, the undead have become socially acceptable.

The standard formula for this kind of film is a simple one: take some easily-identifiable stock characters, preferably of radically different demeanours and outlooks on life, throw them together and allow them to run amok in their newly-deserted surroundings, give them enough time to learn to rely on each other in a survival situation, add some witty one-liners and some inventive zombie deaths, and wrap things up fairly quickly before the audience starts getting twitchy. Easy, yes? Of course, it really isn’t that straightforward, and Zombieland, for its enjoyable performances and at times very witty script, fails to satisfy not for want of containing all of the above constituent elements but on a more basic, fundamental level – the underlying story really isn’t up to much.

Not that the setup isn’t without promise. We are instantly thrown into the immediately recognizable post-apocalyptic world of the undead, seen first through the eyes of a highly neurotic young man who explains that his very survival is surprisingly a result of these. He narrates us through his Scream (1996)-like list of rules key to the surviving of a zombie invasion, rules which will be pretty well familiar to anyone who has seen more than a couple of these films – fitness, making sure the zombie is fully dead, and the all-important observation of proper seatbelt-wearing procedures – the narration accompanied with the text of the rules graphically incorporated into the unfolding carnage. While it is hard to argue with the rules themselves, the exercise itself is gimmicky, mildly irritating and, on a purely practical level, not nearly comprehensive enough.

Our young guide wants to travel from Texas to Ohio to find out whether his parents have succumbed to the living dead or not, and eventually strikes up with a rather deranged truck driver, insistent that they refer to each other by the impersonal names of their hometowns, Columbus and Tallahassee respectively, in case one needed to expediently dispose of the other one. Tallahassee, it turns out, is also on a mission, though a rather less noble one: to find out if this post-apocalyptic world still contains any Twinkies before they all pass their expiry dates.

There is, however blackly, something inherently funny about a world being overrun by the living dead, and the film-makers here are clearly aiming for the audience’s funny bone rather than the cerebellum. In terms of comedy they largely succeed, thanks to their trump card of the choice of actors playing the two male leads – Jesse Eisenberg and Woody Harrelson. With the former playing an even more nervous Michael Cera and the latter seemingly playing a less restrained version of the his Natural Born Killers (1994) role, the two together make for as amusing a chalk and cheese duo as could be imagined; not only does the dialogue fizz with glee at their unlikely partnership, but both actors share a gift for physical comedy which is well exploited by director Fleischer.

Zombieland seems to tick a lot of other boxes too. The duration – a crisp 82 minutes – is on the money for a light comedy, and it is creditable that rather than carefully set up the world of the undead we are dropped immediately into it, dispensing with the all-too-common rigmarole of a long-winded prologue. Comedy is clearly what the director is best capable of handling, and in keeping matters light and frivolous never falls into the trap of either lurching into any kind of inappropriate sentimentality, or attempting to shoot anything genuinely nerve-jangling. Last but not least, a cameo in the film’s second half, while gratuitously shovelled into the storyline, offers some unexpectedly rich avenues of mirth – just wait for it.

Yet for all of what the film does right, there is too much of a lacklustre feeling to it all. Individual reels are fairly well self-contained, but the narrative threads linking them together are ragged and poorly thought out, and as such the film feels like a series of short sketches rather than a unified homogeneous story. One might easily forgive these inconsistencies in the plotting and tone if the film had more of a sense of charm or innovation, but these appear not within its ambitions. The film actually becomes a something of a bafflingly obtuse genre puzzle, for here is a film with horror elements but which isn’t even remotely scary, a road movie but which lacks any real sense of direction, and a character-based comedy but where the most clearly defined motivation is one man’s search for a sugar-rich cake snack. Eisenberg may be a funny performer, but his nerdy loser schtick was fleshed out much better in the recent Adventureland (2009), while the main female character Wichita is relegated to being the all-too-easily identifiable Hot And Fairly Kickass Horror Female. In sketching out such predictable, two-dimensional characters, when the film slows down and tries to form a romantic sub-plot, it falls woefully flat.

Zombieland entertains more than most comedies, largely thanks to its two leads, but the flaws in its conception and execution betray a certain degree of disingenuousness surrounding the film. The reflexivity of Columbus’ ‘rules’ appears to suggest an homage to the zombie movie genre, yet the film-makers fail to display this anywhere else; is the film therefore as much a superficial cash-in on contemporary big-name successes as the likes of Scary Movie (2000), Meet the Spartans (2008) et al? It is a mark of how far zombie movies have come from the realm of exploitation into the mainstream consciousness. But like the elusive Twinkie that Tallahassee is seeking to find, Zombieland may taste superficially deliciously sweet, but it leaves an uncomfortable sickly feeling in the stomach afterwards.