I'm giving it 3 1/2 *s. Not quite a "good" movie, but highly enjoyable, and better than I expected. Not surprisingly, the love story is thin and the special effects, though pretty, are also a bit hollow, a bit too glossy. And there's a whole lot of yelling as a stand in for acting. But it was also genuinely funny at times, especially thanks to Cat Dennings, and Hemsworth makes a charming hothead. It's probably a problem, but also not a huge surprise that I came out of the film more interested in Loki than in Thor: he's a better character, with more complexity built in, and Tom Hiddleston pulled off some nice moments at various places on the Loki-spectrum -- a classic Iago-like poisonous whisper and a couple of glimpses of the son in need of a hug stand out in particular.
All in all, a good time.
5 *s = "WOW!"
4 *s = "Good"
3 *s = "Stupid fun, decent, or at least not bad enough to get 2 *s"
2 *s = "Bad, but not awful, or enjoyable despite its awfulness"
1 * = "The best part was the end, because then it was over."
no *s = "*Deep, pain-filled sigh*...I will never get that [insert running time here] of my life back."