Warm Bodies make it hard. And I'm not even talking about the obvious hurdle, that this is a movie in which the power of teen love cures zombiedom, though that is certainly not a plot hook bending over backwards to appeal to the natural audience for any zombie movie, who aren't likely to take its willful neutering of everything that makes zombies what they are with any special patience (at one point, the blu-ray of Lucio Fulci's genre-defining Zombi 2 puts in a cameo appearance, which is about as galling as if the characters in one of those Garry Marshall "dozens of people on a holiday" comedies started name-dropping Nashville and Short Cuts).
No, that part you can get beyond, if you decide to play fair and maintain your intellectual integrity. What's really frustrating about Warm Bodies is not the story it wants to tell, but the way it goes about telling it, and that's where the concept really starts to just throw away all the audience goodwill it can, even before it started. You need a set of rules, when you're making a zombie film, or any other monster movie; since there are no "real" zombies, of course the writers can start from scratch (in this case, Jonathan Levine, adapting a novel by Isaac Marion), and if that includes the power of love curing them then sure, fine, whatever. But Warm Bodies is unbelievably slapdash about setting up how its zombies work, and that remains a steady problem throughout. It opens with a specific zombie, played by Nicholas Hoult, who can't remember his name but thinks it started with "R", thinking in present-tense voiceover about what his life as a cannibalistic revenant is like, and how rough it is being a zombie with enough conscience to feel bad about devouring humans, though not bad enough to stop doing it, and how hard it is to communicate with his mindless fellows. Okay, so... why is R the True Chosen One amongst all the zombies? Why is he so much more sensitive than all the rest, thereby kicking off the plot? Or is he? Later plot events suggest that all the zombies are equally as sensitive and humane, they just lack the tools to communicate it. But maybe that's not actually the case at all. Not to mention, the degree to which the zombies can't speak is a small point of agony all on its lonesome, because some of them sort of can, and the articulation that any of them possess seems to be largely a matter of screenwriting convenience rather than coherent story logic, especially in the first act.
All of which is the roundabout way of saying: Warm Bodies sure as hell doesn't care if you buy into the world it's creating or not, because it doesn't try very hard to make that world credible. And seriously, fuck that.
The film, anyway, concerns R's chance encounter with Julie Grigio (Teresa Palmer), a human and the daughter of the merciless, authoritarian leader (John Malkovich) of the beleaguered, walled human outpost that is trying its damnedest to outlive the zombie plague. It's a simple, run of the mill matter for R to devour Julie's boyfriend Perry (Dave Franco, the spitting image of brother James), but as he has already found himself smitten with her by this point, he saves the boy's brain, to devour it slowly and thus more fully absorb the memories of Perry's time spent with Julie - that being one of the things zombies can do in this movie, and even given this film's scenario, there are better things that could have been done with it - as he keeps her in his home in an airplane, safe from all the other zombies. Naturally enough, his kindness thaws her ingrained anti-zombie prejudice, once she figures out that he won't be eating her,* and they fall in a kind of love-type situation, that slowly begins to alter R's nature, bringing warmth back to his dead body, and slowly erasing the signs of rot on his flesh.
Alarmingly overt Romeo and Juliet references and all, none of this exactly doesn't work, though the film is perpetually undernourished for what it's trying to accomplish; Julie's conversion from mortal terror to giggly puppy love is accomplished basically in the space between two scenes, the mechanism by which human feelings reverse the zombie disease is left frustratingly magically realist for a script that otherwise does not traffic in that specific type of abstraction whatsoever, and so on. But the central metaphor of zombieism as a commentary on the closed-off emotional lives of 21st Century urbanites is a sound one (as it damn well should be, since Shaun of the Dead made the same observation in a fraction of the time and with considerably more humor nine whole years ago), and the film has a great secret weapon in the form of Hoult, who navigates the tightrope of his character arc well: first he has to be sympathetic enough that we don't hate him but grotesque enough that the rest of the movie has a place to start from, then he has to slowly permit himself to become more alert and emotionally vibrant by tiny inches, so that the character's transition feels natural instead of like arbitrary screenwriting. It is not the finest imaginable performance, but a well more than competent execution of what I don't doubt was quite a daunting challenge.
For all that, Warm Bodies still feels quite a bit lifeless, if you'll forgive an inexcusable pun. It wants to have a tart sense of humor, which comes across mostly in R's sardonic voiceover, but this typically feels plastered atop the film rather than organically a part of it; whatever stabs it has at being an effective teen romance are largely undone by Palmer's fitful performance, in which she never seems more than a few seconds away from just out of nowhere being really angry. It also doesn't help that the "let's establish Julie's character" scenes involve her rebelling against her dad's cruel, capricious behavior, which as it is presented throughout the entire movie is, without fail, exactly the way that a military leader would have to behave if he was going to keep his dwindling population alive, though this is not a sin rare in the zombie genre, stretching all the way back to Night of the Living Dead, though in that case it was deliberate tragedy, not weak screenwriting.
Mostly, though, the film is mediocre, not overtly bad: Levine, in his capacity as director, relies on overbearing song cues to a criminal extent, and takes too many visual shortcuts to posit that his plot is happening rather than actually depicting his plot, though the upside there is that the movie has a tidy 98-minute running time. It's a romantic comedy with zombies that has only sputtering comedy that is mostly undersold by its cast, and zombies that never entirely make sense or feel like a credible threat, and the very best that we can say is that it's a hell of a lot better than the Twilight knock-off promised by the ads. But shit, so is everything.