The sequel "Thor: The Dark World" is a worthy successor to the first movie. It was highly entertaining but it does have one big letdown.

There were some advantages that director Alan Taylor and the writers had in directing the Thor sequel. First, it didn't have the challenge of establishing the franchise. Second, it was the biggest beneficiary of "The Avengers" movie.

Even with these advantages, "The Dark World" still suffered from poor plot development. Most of the complaints sprung from the backstory involving Malekith and Thor's grandfather. The elements of ultimate power represented by "The Aether" which IGN calls "one of those mysterious destructive forces that films like this need in order to further their plot but never properly explain."

An ancient evil lusting after power awakens to reclaim what he believes is rightfully his-not too detached from Megatron's tale..is Malekith. The villain in the movie suffers from being underwritten. He doesn't seem to drive the movie nor push the character to undergo some soul-searching, life-altering decisions. That is something "Iron Man 3" has done very well. Because of the two movies'  proximity, it is inevitable that they will be compared. On that aspect, "Thor: The Dark World" will pale in comparison.

It must be noted that Chris Hemsworth is signed for "Thor 3" while there is no more "Iron Man 4." The last Iron Man needed to be significant, this sequel only needed to further the relationships established or alluded to in the first Thor movie, and it does a good job.

Another factor is that Thor is part of a bigger picture, now being a member of The Avengers. In fact, the story picks up right after "The Avengers" events. Any change would have to coincide with the direction of the general Marvel Cinematic Universe.

This does not mean that it's a bad movie. Alan Taylor's influence in the battle scenes is clear as day.  Hemsworth did describe it as "Game of Thrones without the breasts and cursing." The fight scenes are spectacular, and the humor is served well in this installment. Still, the best parts of the film is when Loki and Thor are together. Loki has already enshrined himself, as did its actor. That's why it's puzzling why there was not enough of him in the film.

"Thor: The Dark World" is a fun ride. It is not a game changer though. That's exactly what it's meant to be.