Sitting back at the end of Colm McCarthy’s adaptation of Mike Carey’s novel (Carey also wrote the screenplay) I was left with a sense of something being missing. A nagging feel of disappointment I couldn’t shake off. It wasn’t simply the three idiots sat at the back of the cinema who would have been better served watching Suicide Squad where being noisy irritating d***s not paying attention wouldn’t bloody matter. It was something about the film itself. I suppose it’s the same feeling teachers get when a promising pupil just isn’t pushing themselves enough. The work is good but if they made the effort, they would be great. The Girl with All the Gifts is in a similar vein.

For the first hour, The Girl with All the Gifts is brilliant. Much in the vein of 28 Days Later this film is unflinching, uncompromising and underlined by a superb musical score Cristobal Tapia de Veer (Humans, Utopia). A score which at times helps to disorient and unsettle and is one of the best things my ears have heard all year.

While the film is stuck in the military base there is a genuine sense of claustrophobia. I constantly felt an atmosphere that was oppressive and unnerving. As well it should be. It was something that owed a debt to Day of the Dead with the sense of cabin fever setting in. The hints of what maybe going on in the outside world in the brief and blunt interactions between the adult characters. A clever device that only increases the intensity of the first half of the film. The mask of civility ready to slip at any second to unveil a sense of nihilistic brutality. It is something personified in the child “hungries” as the antagonists confined to prison cells in the base.

At first these children seem like any other obedient young children in the classroom. Chatty, sweet-natured and inquisitive, but, a whiff of human flesh and they transform into monsters. The moment where our protagonist Melanie (Sennia Nanua), loses control and attacks Gemma Arteton’s surrogate mother Helen is truly startling to watch.

Sadly for The Girl with All the Gifts, once the central characters are forced to leave the base and gingerly head out into the outside world –  things begin to lose their way. Gone is the harsh spotlight on the dark side of human nature of bigotry that reminded me of District 9 and we instead end up with some weird mash-up of I Am Legend and Day of the Triffids. Seriousness gives away to silliness as the films becomes confused about what notes it wants to hit. Does it want to be a hard-hitting slice of dystopia or a semi-comedic, creature feature as we see more of the fungus that has turned almost everybody into flesh-eating maniacs.

One wonders whether Colm McCarthy has done the best he can with the material available. Certainly the film is too long. In the final half hour things really do feel like a drag and the very obvious homage to Lord of the Flies comes off as being something you might see in a primary school Christmas play.

The cast do give it their best shot. Sennia Nanua as Melanie is tremendous. She delivers a convincing performance as a child who may not be quite as naive as she seems but is fiercely devoted to her companions and restraining her own deadly urges. Paddy Considine is excellent. Does it need saying? He always is. As for Gemma Arteton she does a game job in a fairly restrained role, her Helen does have the sense of someone trying her level best to deal with a world she does not fit into.

It is obvious things owe a huge debt to the original I Am Legend novel by Richard Matheson particularly in its philosophical outlook. I certainly give Carey and McCarthy huge credit for bringing some focus back for the film’s ending, which felt like absolutely the right ending, even if the cliché riddled second half made it a predictable conclusion. Nevertheless, it was a welcome antidote to the Will Smith adaptation of Matheson’s work which wimped out on being interesting and impactful to simply be crowd pleasing.

However, the ending does not do quite enough to arrest the sense of bafflement I had over the film’s final 45 minutes. It all became something I couldn’t quite get a grip of, which I suspect is a weakness of the screenplay which seems to struggle to grasp the nettle in the manner of the first hour. Credit where credit is due though, for a director’s feature film debut with a relatively tiny budget of $4 million he imbues the story with an ambitious visual scope. Coupled with strong performances throughout leave us with a good, solid dystopian story.

Unfortunately, there will always be the negative that The Girl with All the Gifts should have been better and that weighs everything else down. It’s a disappointment but an interesting and honorable disappointment.