As a book-to-screen adaptation, I thought it was well done. It far exceeded my expectations as I thought it would be another mindless action movie using a recognizable name to sell tickets. But the producers and screenwriter stuck to many elements of the poem very well. Sometimes the animation does distract from what's going on, but for some of the effects, like the dragon or Grendel's mom's transformation, I think looked better animated rather than as CGI live-action inserts. Changing the dragon's parents was different from the original story, but I think was a better way to connect the battle with Grendel with the end of Beowulf's career. I didn't like Beowulf's friend's reaction at the end. But then again, hero stories are better as tragedies.