I saw this over the weekend and really enjoyed it.
I liked the bit on Krypton, it was suitably alien and I think the mood was right for a planet that was on the brink of blowing up. I thought the fight scene at the end was very good and reminded me of the end of Chronicle but with a bigger budget. The bit in the middle, I didn't like so much.
General Zod was fantastic. Very well acted.
I think there should have been more of a build up to him becoming Superman. This is sort of what I was hoping for, expecting General Zod to be kind of tacked on unnecessarily. Because of this, I didn't really think of it as a Superman story but more of an alien invasion story.
As for being American centric, doesn't Superman fight for "truth, justice and the American way"?
one of these days I'll come up with a better signature