When watching Thor 2 I couldn't help but compare it to the Star Wars prequels. It's a beautifully costumed and landscaped science fiction movie with elements of magic and completely failing to convince us that Natalie Portman and the lead character have more than a casual friendship. They're not in love. They're just not. Not in the first movie, not in this one. I'm not sure what it would take to convince me, but they didn't do it.
The movie even has the three major settings that Lucas likes to use in his movies.
Similarly, the passing of one of the secondary characters doesn't elicit any more emotional response than the passing of Pepper Potts in Iron Man 3 did. But I was pretty sure Pepper was coming back. That death didn't seem to motivate people the way that the death of Agent Phil Coulson did in The Avengers.
Loki and Thor, on the other hand, do a decent job of being brothers. Loki is his usual hard to read self. He's betraying someone, but the question is "who?". At one point I'm fairly sure he even betrayed himself. I didn't really understand what I was seeing there until I sat down to write this and put some thought into it.
It's nice to see Rene Russo getting a battle scene.
The prologue gets repeated during the movie. That's a bit distracting. It works better as part of the movie, but there's some scenes early on that don't make much sense if you don't have the prologue explaining who they are. So what's preferable? The action sequence at the beginning telling the story or the people gathered around a table telling the story more naturally?
We do get to see more of Thor's friends, but not as much as I felt they deserved. Thor has his own Avengers in Asgard and they get cheated. It's like watching Tom Cruise in Tom Cruise's Mission Impossible Starring Tom Cruise. Wasn't there supposed to be other people in this movie? Sif does make it look like she has some interest in Thor and he shows regret that he's not able to return her feelings. The guy who played his swashbuckling friend whose name eludes me needs a good 1920's style Three Musketeers movie of his own.
I didn't recognize Christopher Eccleston as the lead villain at all.
You're going to see Thor 2 largely to see Thor and Loki. They're the stars and they're the actors who make the movie.
If you're looking for movie suggestions, I'd say see Ender's Game before you see Thor 2. In the Marvel Studios series Thor 2 is "also there". But, at this point, criticizing the Marvel movies is like criticizing a Pixar movie. The worst of the lot is still better than so many other movies out there. Meanwhile, making the best Fantastic Four movie still gets you the death penalty in some more repressive countries.
If you see it, be sure to sit all the way through the credits. There are two scenes before the lights come back on.