This movie does belong in a class by itself: Even worse than utterly terrible. I have been an aficionado of 'bad' movies for quite a long time, adoring those movies which only a group of friends and many drinks makes enjoyable. This movie was in fact so amazingly bad that I could not watch it past the first half hour or so. I only watched the rest via fast-forward the next morning. I've seen many films worse considered classically bad, this one beat them all hands down. I even had to start referring to possibly similar bad movies by saying "They may be in the NS3 category". There are those bad movies that are MST3K fun and then there are those that make you wish you had a sharp object to commit suicide with, this one is the latter.
This franchise went from excellent original fantasy, special effects for the genre, and well written characters to bad acting and writing in part 2, to movie of the week actors and rubber puppets in part 3. It's amazing how a film franchise that had such good promise sank faster than Lips Manless after taking "the bath". Especially if you're considering getting this for the kids, at least treat them to the original movie or something like the Peter Barnes inspired fantasy miniseries' from the late 90s.