Beowulf isn’t going to please literary scholars, and not only because it contains far more action than alliterative verse. Screenwriters Neil Gaiman and Roger Avary have made significant alterations in the basic plot of the centuries-old poem, yet the irony is these narrative detours are the movie’s main achievement. Rather than hero worship, this mixes a modern sense of anti-heroism with a healthy dose of Greek familial tragedy. As for the much-touted motion-capture animation overseen by director Robert Zemeckis, it’s still not ready for prime time. Too often the picture resembles an animatic, or rough animated storyboard, for a “real” movie such as The Lord of the Rings. (Though Angelina Jolie, as a shape-shifting temptress, makes a natural fit.)