Rudolph travels to the island of misfit toys to help the elf dentist treat the lion toy. As they sail back they get caught in a storm and meet the Hippo Queen who offers to fix Rudolph's nose if he wants it done. While he is away The Toy Taker raids Santa's toy warehouse and takes all the toys. Rudolph sets out to find the Toy Taker and get all the toys back in time for Christmas by using the island of misfit toys as a trap to draw him out.
Dear Lord but this is one cheap nasty little cartoon! Ignore the actors listed in the cast list - just because they managed to pay a few big names for a day and a half's voice work doesn't mean this film is any good. The plot is a reasonable attempt to draw as many films out of Rudolph as possible and, on paper, is a reasonable sting operation but the delivery is awful and ruins anything that might have been called potential.
The godawful songs are part of the problem - they seem to happen after every few lines of dialogue all the way through. It makes it impossible to bear - it really is awful stuff. The animation is also pretty bad. That might seem a bit unfair considering it looks OK and is computer animation, but it is the sort of animation you get in cut scenes on average games on your PC. The camera moves very slowly, the characters cannot move very fast and none of them are lip-synched at all!
The fancy voices do nothing at all to improve it. Dreyfuss does some rubbish Snowman narrator but Jamie Lee Curtis dons a horrible accent to do a hippo queen! (was she trying to hide her identity from shame?). Moranis has an OK character visually but he does nothing with it and the absurd songs and voice only serve to the character of any menace he had before he spoke.
Overall I can only advise that you do not make the mistake that I made by watching this. No matter how demanding your children get, don't use this film to placate them - making them sit facing the wall for an hour would be preferable.