The action scenes were dull and utterly anti-climactic. Oh look, Superman's beating **** up. Will he win? No **** he will. There was no tension to them.
A lot of this also has to do with the way the villainous Kryptonians were portrayed. In Superman II they go on a destructive mission to draw Clark out and destroy him prior to ruling over Earth.
Superman's true Kryptonite is his inability to be everywhere coupled with a great desire to protect humanity. Apart from Faora once saying this out loud, there was no real pressure on this ideal. They're quite happy to put zero pressure on him and just let the World Engine do its work.
Furthermore, Zod clearly knows that he NEEDS to kill Clark in order to harvest the DNA from him and begin rebuilding Krypton anew. What does he do? He heads off to reclaim the Genesis Chamber, say bye to Jor-El and then heads over to take a frontrow seat as Earth is terraformed.
He doesn't even consider 'should I maybe protect the World Engine from Kal-El?' or 'should I proactively seek him out and eliminate him before he ruins our chances at a new Krypton?' Nope, I'll just let him destroy it and then later on bemoan him spoiling everything. Good job at being a reactive villain and then whining about it.
The major issue with blockbuster films is that it's about scale and that in turn ruins the saddening loss of individual lives. The death of one is a tragedy. The death of a million or the destruction of half a city is just a statistic. It has no emotional weight at all.
Bruce saving Gotham from the League of Shadows was mainly to protect and preserve what his parents had worked so hard to build. Even in the third film, it's that emotional attachment to Gotham that drives the film. Was that there in this film? Nope. Because Clark's still debating over where he's from and where his home is. That's fine, but find SOMETHING to hinge the film on. Have him embrace the planet as his home early on and SHOW him putting in the love and effort to improving it prior to Zod turning up. Not just hanging out on the farm and waiting for **** to go south.
Yes, I get the fact that he's not sure what humanity would think if he revealed himself, but like the Priest said, he needs to take that leap of faith. But much earlier on than halfway through the second act. Then at least when Zod lays waste to his adopted home, he FEELS it. Then he gets mad. Then he goes on a mission to stop Zod.
THEN the action scenes whether long or shot have a weight to them. Death then has a cost to it. I was welling up during the scenes involving both sets of parents, Clark and Lois. Imagine action scenes exploiting that emotion too. That's what was missing. And it really cost the film a lot. Not to mention the flashbacks being scattered as if fired through a machine gun. They worked a charm in Batman Begins because they were measured and were chronological to a point. Here they were all over the shop. But that's a story for another post.