If you are familiar with Tolkien's "the Hobbit" and go expecting this to be a film version of that book, you will be disappointed.
Instead, this film is a prequel to "The Lord of the Rings", adding material from the appendices and from "The Silmarillion" to pad out the story (to three films!) with events which, while they would have occurred during the time frame covered by "the Hobbit", are not mentioned in "The Hobbit" at all. Meanwhile certain events in "the Hobbit" are deleted, added to and, rather arbitrarily, changed.
I enjoyed the film, but it's not "The Hobbit" and look forward to when all three "Hobbit" films have been released on video so someone can edit it down to one film which will be as close to "The Hobbit" as we can get.
The first 40 minutes of the film are superb.