You’d be forgiven for confusing Private Peaceful with one of this year’s Best Picture nominees at the Academy Awards. Both are based on a Michael Morpurgo novel that was adapted into a successful stage play. Both feature sun-dappled depictions of rural England, decidedly dodgy ’Westcountry’ accents and a sentimental, yet powerful take on the horrors of the First World War. Both include talented young British actors alongside solid veterans.

But – and here’s the rub – only War Horse had Steven Spielberg in the director’s chair. Pat O’Connor (Circle of Friends, Dancing at Lughnasa) is a reliable pair of hands, but his first film in 11 years has more in common with the gentle, Goodnight Mister Tom school of period dramas than big-budget, Oscar-bait epics.

On the eve of a court martial and possible death sentence on the Western Front, Tommo Peaceful (George Mackay) looks back on his life – a bucolic, but blighted Devon childhood, his protective older brother Charlie (Jack O’Connell), and the gamekeeper’s daughter (Alexandra Roach) who stole both their hearts.

Though its narrative takes in family tragedy, pre-war poverty and the senselessness of a military force executing its own men for supposed cowardice, Private Peaceful’s a remarkably bloodless film. The production’s budget looks to have been miniscule – with over 100 investors stumping up small sums to finance the shoot – and while intimacy’s a laudable approach when it comes to character interaction, any sense of jeopardy is lost from trench warfare scenes when only about 20 soldiers seem to be fighting the battle.

A funereally paced first act in the Devon countryside delays the introduction of the excellent O’Connell and Mackay as our leads and Simon Reade’s screenplay, adapted from his play of Morpurgo’s novel, veers between signposting dialogue and unconvincing melodrama. There’s a sweet scene in which the young Tommo, Charlie and Molly play together in a babbling brook – only for the heart-warming tone of the scene to topple when Molly blurts ‘I want to die because no day could be as good as today’, just to make it really clear that these characters are happy but in the future they won’t be.

Once war’s broken out, with Tommo keen to join and the more level-headed Charlie politically opposed to the conflict, the emotional blackmail of the military’s recruitment drive is smartly depicted in a town square scene. Sadly, the Sunday serial childishness of the piece comes into play again here, as a genuinely terrible elderly actress hammers home the point of the sequence by theatrically screaming ‘Coward!’ at the initially dithering Tommo.

It’s frustrating, as Morpurgo’s sensitivity and ability to humanise an inhuman event should allow for poignancy. There’s quality in front of the camera, with John Lynch barking to great effect as a harried drill sergeant, Maxine Peake an affecting single mother and Richard Griffiths and Frances de la Tour permitted a brief reunion of their History Boys double act. And though the innately physical O’Connell would have been a better fit as Tommo than Mackay, there’s a convincing filial chemistry between the two.

Private Peaceful has important messages to teach young viewers about the madness of war but it belongs in ITV’s autumn scheduling, not on the big screen.