This movie does a lot of things right, especially considering the budget (etc) of the filmmakers. The music fits the bill really well, the Icelandic language and scenery is beautiful and about as authentic as you can get. Basing the story upon a saga, and using its conflict is also a good move. Even the costumes and weapons looks authentic, even though I do not know enough about this to judge. Having all of these elements in place, together with some of the stylistic choices made, makes for the perfect formula of a new kind of movie: the viking movie. Taking the best parts from the "spaghetti western"-genre and putting it into a completely different environment, basing it on completely different material, and do an honest attempt to be historically accurate. Sadly, few movies followed this movie's footstep, and so we are (mostly) stuck with horned helmets and giant berserkers.
The problem with this movie is its story. Its taken from the sagas, but they could have made a bit more effort in making it understandable for an audience not familiar with the sagas. There's many characters that's hard to keep track of, and rituals that's not properly explained. You do get the gist of it by watching the movie, but I can imagine some quite simple steps, like more obvious visual cues separating the characters (like how the three main players in the good, the bad and the ugly are all very distinct) and a bit more establishing of the characters and relationships in the beginning of the movie.
All in all, this movie does a lot right, and I wish other filmmakers would follow up the foundation laid by this movie. We should have more (viking) movies like this.
