It had been a while since I read Prince Caspian so before going to see the new one recently, I visited my local library and "rented" the old version on VHS. To the best of my memory it was itself quite faithful to the book. The differences between the old and the new Prince Caspian videos are multitudinous.
I must say that I was impressed with the faithfulness of the first new movie to the book "The Lion, the Witch, and the Wardrobe." I was less impressed with the second offering. It seems to me they took a lot more liberties with the latter than they did with the former. The opening scene of the first movie was absent from the book though, more or less, implied in it. Further, the scene on the ice was a clear departure from the book. Other than that, with the possible exception of a watered down version of the anological trilemma, there really wasn't a whole lot different between movie number one and book number one. By analogical trilemma, I mean when the professor is reassuring the oldest brother and sister that they ought to believe their youngest sister about the magical wardrobe as incredible as it may seem.
So there were too many changes in Prince Caspian the movie from Prince Caspian the book, in my opinion. What other complaints are there? Well, there was way too much fighting in this one (and also the first one). Yes, it is true, that there is fighting in the books. Moreover, violence itself is not a problem. There is plenty of violence (and sex, now that you mention it) in the Bible itself. My problem is not with violence per se. In fact, I rather enjoyed the first installment of the Saw series. Those movies are about a man who enjoys torturing people in unique ways, albeit with a view to ethical reform if the people happen to survive the ordeal (they normally don't survive). My problem is with violence as a spectacle which takes away from the real story under consideration.
And what is the real story of the Narnia series and, more particularly of Prince Caspian? I remember watching an interview of the cast of "The Lion, the Witch, and the Wardrobe" and one of the people said that it, the first movie, was just a good story and can be interprated any way one wants. Not so. Jack clearly intended certain meanings to be taken from his Narnian series. He specifically said, in a letter to a child, that Aslan is supposed to be a real person who really exists outside the novels in our world. He then went on to imply that that person is Jesus Christ. It is not that Narnia is an alegory for Christianity. Rather, Narnia is a parallel, albeit fictional, Christianity you might say.
And there are certain ethical themes in the various books. For instance, Edmunds lust for Turkish Delight is an illustration of gluttony (one of the seven deadly sins). His gluttony lead immediately to the negative consequence of the betrayel of his friends and siblings. And after that, it led to his death. Or, it would have, if Aslan (who is Jesus, remember) did not die in his place on the stone table (the ten commandments, by the way, were written on stone tables in our own world). The Chronicles of Narnia are blatantly, though not explicitly Christian stories. Now, even in the new movie Prince Caspian they included the ethical idea of faith. If you have seen the movie or read the book, you know that the older siblings do not believe the youngest's eyewitness testimony to having seen Aslan in spite of everything that happened in part one. In other words, they had a lack of faith which is sin.
But, while this ethical idea was included, along with the heinousness of pride, the focus of the movie seemed to be not primarily on ethics, which is closely linked to theology in my view. Instead, the focus seemed to be on fighting battles. And such "cheap thrills" normally imply a lack of substance. But there is no lack of substance possible when one is talking about Jesus so all the fighting was superflous at best and watered down the real story at worst.
Now, this is not to say that the movie did not have its good points as well. I enjoyed the movie (though I have other complaints as well I'll spare the reader here). I thought prince Caspian was cast much better than he was in the older movie. That is one example of a positive. The special effects were good. The movie seemed more mature than part one which is a nice feature for adult audiences. And it did stay close to the essence of the Narnia series of books as a whole and Prince Caspian in particular. So it was not all bad.
In the final analysis I would have to say that I could pobably give it five stars if there was less gratuitous violence and less deviations from the book as I remember it. For these perceived flaws I can only give four stars or less. I do recommend it for fans of the books, the older movies, good fantasy fiction in general, Christians with an imagination, and everybody else.