I must admit I have not seen Troll Hunter, though I really want to. So I can't compare.

As for the found footage aspect, Goldthwait mentioned that he tried to make it as seem as real as possible, with minimal edits (there's this awesome single take that lasts 19 minutes); so as to make it look like the footage was actually just found (he made a joke about the fictional finders of those other found footage films think, "hey, if I edited this footage of people getting raped and killed it would make a great movie"). Anyway, it works.

And it's not so much a monster movie as a mockumentary that goes wrong.