This is one of the worst Marvel films I've seen, despite its star acting cast. Like others, I don't know how they possibly roped Natalie Portman from her excellent role in Black Swan to this the awful role she had in Thor.

Character interactions were extremely flat and not developed. Thor's change in attitude is sudden, unexpected, and completely against all his character development up to that point in the film. Loki's change in attitude is confusing and not developed, with the 'twists' in the film being completely nonsensical, and his story has more loose ends than a bowl of spaghetti.

All the other characters are completely undeveloped, with Heimdal, Thor's friends, and the other 'Earthlings' having no remotely worthwhile lines. The interactions between Thor and SHIELD do not even remotely make sense, and fall apart upon the simplest of questions, again with enough plot holes and loose ends to make your head spin.

The costume designs were awful—the armor looked like cheap, overly-shiny plastic that is intended solely to sell merchandise to children. The sets in Asgard were CGI and not even very well done, as well as completely un-interactive (the characters spent like 80% of the film in Asgard sitting on the rainbow bridge or in Heimdal's rainbow building).

I did not find anything redeeming about this film except that I got to look at Natalie Portman, but then I had to cringe every time she has a line so bad that it could fit into Star Wars: Episode II (which was about half her lines). The 'romance' with Thor was ridiculous and completely lacking any spark or realistic dialogue, again just like Episode II.

The ice giants story that the film was supposedly revolving around seemed like a minor footnote, with a preachy ending that doesn't make any sense for either one of the characters' actions. Loki's action at the end of the film also makes no sense, but I'm sure it sets us up for a hopefully-less-terrible sequel.