I just saw this film in San Francisco. To be honest, I wasn't expecting much from this troll myth but some gory violence and primitive script spoken with unintelligible accent.
So I was more than pleasantly surprised when the impacting music and the spectacular pristine scenery quickly took me into the world where a giant's young son experiences a major trauma of getting his dad killed in front him and grows up alone and isolated with retribution in mind. So this Grendel is actually portrayed much more as a human with an unfortunate fate than a murderous monster without any personal identity, and I liked that. Beowulf who steps up initially to exterminate the troll starts sensing and detecting that there's more to this huge person than what was told of him, particularly after one of the troll's visit to the king's beer house (in which all Grendel did was pee on the front door to tease the warriors inside -- this scene was really funny). A great sense of humor with a modern twist is felt all throughout this film and really lightened up this stark ice-clad Scandinavian setting, and save the film from being unnecessarily dark and serious.
All the actors were great. Skarsgard (Hrothgar) and Butler (Beowulf) in particular, fit right into their roles. Although Sarah Polley's accent did't really mesh with the rest and her portrayal of the character was a bit too modern at times, she played the part of the mysterious firey witch really well.
Gunnarson's interpretation of the tale, making Beowulf's compassion towards the troll and those around the troll an integral part of the epic, really sets this film way apart from the rest of the average monster movies, and makes this a classy entertainment film of its own. No, it's not your typical trashy monster movie. It's WAY better than that and IS worth your viewing time if you have good enough a taste for a quality film with substance and many subtleties.