This movie is surprisingly not about mentally challenged internet troublemakers that mock suicidal teenagers, it's about actual mythological trolls. They eat rocks and Christians, they turn to stone, and they are huge.
The film uses the "found footage" gimmick to give a Cloverfield/Blair Witch kind of perspective to the story. The set up is, a group of film school students decide to film a documentary about an infamous bear poacher in the Norwegian wilderness. Needless to say, this character turns out not to be a bear poacher, but a troll hunter, hence the name! As the documentary crew discovers, his title does not imply that he tries to get dates with Snooki in Jersey, but that he actually hunts down giant trolls in the middle of the night and kills them. As the crew and the troll hunter warm up to each other, this mysterious man reveals all the ups and downs of his career to them.
Of course the found footage contains many troll hunts and the special effects are convincing enough to be entertaining. There is not much of a plot as the group drives from troll to troll for some half-baked reasons. The characters are portrayed as realistic people. There is a touching moment when the troll hunter describes himself as some sort of mass murderer, when one of the young filmmakers suggests that he is Norway's greatest hero. Once in a while the man does show that tiniest bit of admiration towards the creatures that he relentlessly slaughters for a living, kind of like Reggie White admired some of the Quarterbacks he slaughtered.
The Troll Hunter is a pleasant low budget surprise in the same sort of way that Monsters or District 9 were. Overall the film feels more like a documentary than any kind of monster movie. It's interesting enough to enjoy, and simple enough to follow even if you hate foreign films, but probably not a movie you could watch over and over.