Apparently some people are confused by the film. I actually stumbled across a review, somewhere in the vast internet, by some gormless git who gave "TrollHunter" low marks because it wasn't scary enough. Well "This is Spinal Tap" isn't very scary either. That's because both films are COMEDIES! I guess the Norwegian sense of humor is a bit dry for some entities.
It's true that unlike "Spinal Tap", "TrollHunter" is a horror film which utilizes the requisite conventions. It's also shot in really stark and beautiful places in rural Norway and has trolls. It has great fun with the conventions of troll lore like their fondness for the underside of bridges and their ability to smell the blood of a Christian man.
Otto Jesperson, who plays the title character, is great. This film has just become available on Netflix. I highly recommend it.