One of the interesting things about international genre cinema is witnessing how long and in what ways Hollywood and breakthrough American independent movies often trickle down and influence aspirant filmmakers. With the Sundance entry Trollhunter, Norwegian commercial helmer and debut writer-director André Ovredal delivers in fitful fashion on a simple premise that its title reflects quite literally.

The story, framed in a mock-documentary format, centers around three college kids who set out with a video camera to investigate mysterious occurrences in the nearby mountains and woods. After tracking down a grizzled bounty hunter, Hans (Otto Jespersen), a sort of Norwegian Van Helsing, they convince him to let them tag along, and learn of a sprawling governmental cover-up of the existence of trolls.

Trollhunter‘s special effects work is impressive, especially for a low-budget effort. And some of the scenes are incredibly imaginative in their quirky detail, as when a group of Polish subcontractors posing as painters start wrangling over the price of a bear carcass used to frame the aftereffects of an incident as a mauling, or when a veterinarian explains why some trolls explode and others turn to stone when exposed to light.

Still, for all its technical accomplishment and cultural specificity — including some natural scenic beauty, wonderfully captured by cinematographer and sole camera operator Hallvard Bræin — Trollhunter never really clicks on all cylinders. It’s mostly droll, but it doesn’t consistently foment either dread or delight, owing mainly to the need for sharper characterizations. Part of what made The Blair Witch Project so successful was a real sense of bickering divide and tension amongst the characters. That never develops here, and so the amusing moments aren’t quite steady enough and don’t gather enough downhill momentum to qualify the movie as anything more than a cultural curio. (Magnet, PG-13, 103 minutes)