I wasn't expecting this movie to be much more than a cartoon movie from 1978. I have no problem with "primitive" movies, and the word "dated" is meaningless to me where it comes to movies. I mean, newer animation movies aren't necessarily better than old movies I think, and sometimes that "dated" animation even has it's own charms. But I think this movie had some serious flaws that have nothing to do with it's year of origin, or the state of technology that was present and available at the time it was created.
To begin with, a pity is of course the fact that although the crew's initial intention was to make a cartoon version of the entire trilogy, after the battle of Helm's Deep they ran out of money and decided to let the end credits roll down the screen. But I'm afraid this incompleteness is not the biggest flaw of this movie. Note: I heard an even worse and rarely known sequel was made in the 80's, to cover the remaining part of the story.
Let me go into a little more detail concerning my opinion on the movie as it exists, despite the incompleteness of it. There were a few things I surely liked about this movie. First of all the story of course (be it not completely covered), but I guess Tolkien should be credited for that and not the crew of this movie. Secondly, I like to see as many as possible interpretations of this great and beautiful world created by Tolkien, because I hate my imagination to become biased by any single interpretation of what any of the characters or locations look like. This movie is just another visual interpretation, and I like it for that, even regardless of quality. Third of all I liked the drawings (background, etc.), at times that is.
Let me declare why I say "at times": The partially beautiful, colorful and charming cartoon parts in this movie are all too obviously interwoven by low-budget camera scenes of flesh and blood extras with a frequency that increases as you proceed through the movie into parts of the story with more action. Either to save money or because the crew thought this made the action scenes look cooler, the crew made the pittyful decision to record scenes of flesh and blood actors, and overlay them with a 4-color palette in a failed attempt to let these scenes match with the cartoon scenes. This could remind you of crossover movies like "Who framed Roger Rabbit", but with this movie I assure it's totally different. Rather than a tasteful combination, in this case it's obviously a failed attempt to hide the fact that some parts aren't really drawn cartoon scenes. The with this is that these scenes are, mainly because of the 4-color-palette, so ugly they made me think that this is what it must look like when you're looking at reality through a thick layer of mud.
Additional problem caused by this: the result is that this movie is a mixture of two differnt "styles" that don't fit together at all in my opinion. To begin with, the cartoon parts are mostly beautiful and the other parts were, as I said, very ugly. But apart from that and maybe even more important, the stiffly moving but charming cartoon drawings of Gandalf and the hobbits just don't fit with the smoothly moving but awfully colored Nazgul or the Orcs, for instance. In comparison, those latter suddenly appear to have extremely un-cartoonish physics and locomotion which of course perfectly reveals the fact that you are looking at flesh and blood actors, even when through 4-color palette to make it look more primitive. Needless to say I preferred the stiffly moving but colorful animation of the cartoon parts.
Another thing I really hate is the "casting" of the cartoon characters. It seems the drawers didn't spend a lot of time thinking about how they were gonna draw the characters. Aragorn looks extremely unfriendly and unsympathetic, more like a bully than like a mysterious but well-meaning stranger. Gandalf and Saruman look exactly alike which was very confusing. Boromir looks like a Dwarf, Elrond doesn't look like an Elf, Legolas looks kinda like an Orc with blond hair and Sam looks like a retard which I think is an insult to his very important character in the story. Frodo is at least one head taller than his three fellow Hobbits, which kept disturbing me, and at the end of the battle of Helm's Deep finally, it got even worse when what I assumed was Gandalf riding his horse, appeared to be Theoden.
Conclusion: As a devoted Tolkien fan, I really wanted to see this movie, and I'm glad I did. But I really feel no urge to view it again any time soon. As said and explained before, I think this movie has a lot of serious flaws that are not the result of that fact that it was made in 1978, little more than 25 years ago.
Review by RagingR2 from the Internet Movie Database.