Thor was supposed to be just a teaser before the release of Marvel's main attraction this year Captain America: The First Avenger and something to help pass the time until Joss Whedon's The Avengers hits the screens in 2012. It turns out Thor is more than that.
Obviously, the main purpose of the movie is to introduce the character of Thor, one of the avengers. And it does quite a good job of that. While the story itself is predictable and cliched, the film is well paced, well acted and well directed by the competent hand of Kenneth Branagh. His Shakespearean expertise comes in handy during the scenes involving the relationships between Odin and his sons Thor and Loki. And while Anthony Hopkins is expected to perform at top level, the real stars of the show here are Chris Hemsworth and Tom Hiddleston, playing Thor and Loki.
Chris Hemsworth is surprisingly good as the flamboyant Thor: charming, confident and audacious. Not exactly Robert Downey Jr.'s Tony Stark level, but somewhere near it nevertheless. He is helped by a restrained script which is not overplaying Thor's ignorance of Earthly matters and customs to the point of silliness, focusing instead on good-natured humour and quickly putting Thor in sync with the place - in a true godlike manner.
Tom Hiddleston as Loki is lean and mean, his calm composure providing a good counterpoint for Hemsworth. Natalie Portman doesn't really have much to do in Thor other than smiling silly and falling for Thor in ten seconds. On the other hand, Stellan Skarsgard is always good to see. Fans of Marvel's series will also be delighted to see a couple of cameos: by another avenger and by Stan Lee, the comic's creator. Not to mention the amount of fan-service spread throughout the movie. And in the unlikely case you haven't heard this yet, there is a scene after Thor's ending credits, so don't rush to the cinema exits.
A high point of the movie is the design of Asgard. It is huge and megalomaniac, but clean and in some ways reminiscent of the game God of War environments. The night scenes set in Asgard are beautiful to behold and deserve a special mention. Bifrost, the bridge between the worlds is also spectacular, albeit conceptually somewhat different than the comic's original and the mythological original of the comic's original (chew that).
On the bottom side, 3D is pointless for this movie. Skip 3D if possible, save a few bucks and watch Thor in 2D. And there is also the mildly annoying issue of the politically correct presentation of the Aesir: neither the comics, nor Norse mythology have black and Asian Aesir in them.
So, to conclude: Thor is an entertaining movie doing more than a fine job filling the gap before Captain America and his shield arrive in July.