Light and frothy, Thor is essentially a kids movie, with shiny costumes and goofy characters. As such, it is harmless summer entertainment, though not very compelling, with little real danger or violence and stakes that are so ridiculously huge that they have relatively little urgency.
The sets and effects are big and overblown, and they achieve a certain kitschy grandeur. Most of the characters are given short shrift, especially the earthly ones, who are entirely one note. The only actors who come out of this looking good are Chris Hemsworth, excellent in his first starring role as Thor, Tom Hiddleston, Machiavellian and (relatively) complex as Loki, and I suppose Idris Elba, as the intimidating Heimdallur. The plot is both convoluted and simplistic, with an akward structure attempting to support universe-spanning events rendered in the most obvious comic book-y way; the type of thing where characters can destroy inter-dimensional pathways with hammers. That might be the best way to think of the movie: as a sixties-era Marvel comic writ large. It has an innocence and cheerfulness that mostly makes up for its general silliness. On the other hand, I can easily see the general cheesiness of many scenes leading it to become a cult classic 20 years down the road, watched only for its camp value. As you can see, I'm of two minds with this one, but I think its good nature wins out. It's dumb, but not stupid, tiresome, or offensive.
Rating: 6/10 Stars.