The following contains spoilers. Stop reading if that matters.
Summary: good movie. Watch.
The movie takes the overall mythology forward. Indeed one could argue that they try to hard in connecting the various elements of the Marvel universe. Example the references to the New York events from The Avengers. The TV series Agents of Shield has the same issue. I suppose they had to explain away the fact that Thor returned to earth the last time without looking up Jane Foster.
The plot has too much going on. That would be the one complaint. Still the actors seem to have good chemistry. Loki still manages to dominate every scene he is in. His “death” in the dark world is a kind of weak element. So his resurrection is not unexpected. The only question is, what happened to Odin?
I suppose this means any sequel can completely stay away from Asgard while it is being reconstructed after the destruction by the dark elves.
In The Avengers, it took the resources of Iron Man’s billions plus Shield to create the required force field using some kind of transmitters. He ask it took is some metal rods and a couple of transistor radios. Maybe technology advanced a lot in the interim. Oh well.