So, I went into this knowing pretty much nothing about Thor, be it the comic books or Norse mythology. What I knew was that Thor was the good guy, Odin was his dad and he only had one eye, and Loki was the bad guy. However, the comic to the right misinformed me. I thought Loki was the god of FIRE, not ice. Silly OOTS.
Anyway, overall the movie was pretty good. Good action sequences, good non-action sequences, some great one-liners. The acting was well done and the dialog sounded natural. (Always a plus; that's one of the reasons I despise Harry Potter and the Half-Blood Prince.) I knew a few other things about Norse mythology from reading The Sea of Trolls by Nancy Farmer. Good book, incidentally - I've not read the other two in the series, but I've heard that they're also pretty good. Anyway, that introduced me to the concept of having the nine worlds on the great tree. So see? I wasn't COMPLETELY ignorant.

The characters were nice. And here we come upon my problem with this movie. We had Thor, our main guy. And we had Loki and Odin. We also had three of Thor's buddies, Odin's wife (don't remember her name), the head troll guy (don't remember his name either), Agent Colson, whats-his-face with the bow, AND the three scientists. Plus lots of extras. Now don't get me wrong, this isn't too terribly many characters. The problem was that all of those people, with the exception maybe of Colson and whats-his-face, weren't just supporting characters. They were extremely integral parts of the story that ALL had their OWN story. For me, going in without knowing the story of the Avengers, these incredibly unique and different characters lost a lot of flavor. Except maybe with Colson, since I saw him in the Iron Man movies. But for a cast of characters that big that requires so much information about all of them, something got lost.
I didn't connect with any of the characters. Sure, some of them seemed interesting and I wanted to see them more fleshed out, but they were all kinda flat. Their stories - which, from what I'm told, is an integral part of them - were lost, and much of who they are was lost as well. Which was kinda sad. This movie had so much potential and so much going for it - but unless you're a big Thor fanboy or fangirl, these characters have no impact on you. At least in Iron Man I learned enough about Tony Stark for him to drive me stark raving mad every bloody time I watch the second movie. I like the first movie - he was a good guy. THEN he went and turned into some kind of arrogant jerk again. Which I found just maddening. At least Batman didn't seem to be always acting for himself. Whats-his-real-name-who-was-Batman (I'm running a lot of blanks today for some reason) may have been a jerk as his cover, but Tony Stark took that jerk-ness and put it to an exponent of 100. And everyone knew he was Iron Man; he made no attempt to hide his real identity. GAH!!
But anyway, you see what I mean. Tony may be annoying as heck to me, but I can understand (kinda) where he comes from. Because they took time to show us what he could be in movie 1. Thor didn't take that time with any of its characters, and that's what hurt the movie.
Which was sad.
Overall though, good movie.
-enna