The War of the Rohirrim is not a bad movie. I just saw it and enjoyed it. First of all, it does a good job adapting the story of Tolkien's Apendix. The writing, plot, spectacle and substance is pretty good. The animation while not very good in an action scenes is pretty good in a lot of sections. The suspense is pretty good. The use of the orcs as a sideline is pretty good and superstitions about Helm being used a scare tactic for the Riders of Rohan is a pretty good. The winter aesthetics are also fantastic. The voice overs with Éowyn are great and they do a good job making it clear that the story is a long forgotten tale lost to history.
This film may not be a critically acclaimed anime masterpiece or a major box office success. But it will always be remembered among the other Tolkien adaptations over the years and Middle-Earth Fans who like Anime will see this as a cult classic.