For a diminutive giant-hunter in small-town America, flesh (lump) eating beasts are nothing compared to the misery of everyday school life. Bullied, ignored and ridiculed, little Barbara can cope with actual giants, but struggles with bullies, teachers, gym class and the intricacies of social interaction. Hunting the mythical creatures serves as her only escape in life, even if she doesn't appear to be very good at it.

That's not entirely her fault though; giants aren't real, after all. Jack the Giant Slayer or Troll Hunter this ain't; the not-so-actual 'giants' are purely fantasy, witnessed only fleetingly and serving as great big straw men for Barbara to chase, an outlet for her fear, anger and unresolved issues at home. You thought you were getting a whimsical fantasy action film? It's The Bridge to Terabithia all over again.

Thankfully, for all its YA Fiction tendencies, Anders Walter's fantasy drama juggles its varying genre elements well. I Kill Giants is more competently made than any Harry Potter film, Hunger Games entry or Wrinkle in Time, quietly living and breathing an emotional maturity which should appeal to its adult audience more than one might expect. Don't let its precocious bunny-ear wearing protagonist put you off – yes, she's awful but that's kind of the point! I Kill Giants tackles the reality of such archetypes, and specifically how much of a pain a girl like Barbara might be to live with. There's a reason the Dursleys made Harry Potter live under the stairs.

Its indie cast is likeable but non-showy, with Imogen Poots and Zoe Saldana – plus a bizarre cameo from Noel Clarke – making up the talent and breathing life into their flimsily-written characters. The young cast are strong too – Madison Wolfe's character might be an irritant, but she absolutely sells the kid's pain and determination, in spite of such distracting affectations as the Bob's Burgers bunny ears and oversized glasses.

Those who tuned in just for the giants may be disappointed, but there are still a few, and they're handled nicely considering the low budget and story at hand. In spite of the shaky CGI, the giants are suitably majestic and haunting, shrouded in mist and spooky woodlands. They're nowhere near the main focus, but they look good enough that they could well be, smoothly employed in a story with shades of The Iron Giant, A Monster Calls (which, for all its similarities, this one predates) and classic Spielberg.

Too overtly childish for most adults, yet too mature and slow for young children, there's a risk that I Kill Giants might not be able to find its audience, but it should appeal to fans of the comic book (which is replicated panel-for-panel, in places) and those who enjoy slightly off-kilter fantasy indie cinema. In spite of my cynicism and distaste for precocious kids, even I was left with a tear in my eye as the end credits rolled.