Giving this movie a grade of C+ should not be taken as an indication that I did not like it. I actually enjoyed my time in the theater. But, grading it on the curve against other comic book movies, like Iron Man and The Dark Knight, I think a C+ is actually pretty generous. Thor is as bright and shiny and powerful, yet as empty and emotionless, as the Destroyer robot sent to Earth to kill him.
The plot and some of the acting is seemingly Shakespearean. Yet it only seems such. It borrows the pomp and swagger of the bard, but fails to deliver motivation for the characters. It is completely contrived and situation-driven. In that regard, this is just a comic book movie. The characters all behave with the shallowness of their comic book counterparts and bright colors and swirling action are an attempt to disguise it.
What saves the film from being a complete disaster is the obvious enthusiasm for the project by all involved. The actors and director are all in. The effects team does a bang up job. If one can ignore the emptiness below the surface of the silly story, as well as the unusual emptiness of the cities and towns of Asgard, New Mexico, and the Frost Giants world, one can have an amusing couple of hours.