Just saw this, but, uh, how in the world is this supposed to have been "dark" or "grim" or "brooding"? Superman saves the WORLD, not to mention a busload of children, oil rig workers, doesn't rise to the bait when someone's attacking him and takes the high road, grins like an idiot when he learns to fly, only kills the main villain because the guy literally forces him to, and only fights in the city limits because, again, the villain forces him to. It's an origin story. If he'd magically been a million times better and stronger than Zod from the get-go and flew the two of them off into space it would have utterly ruined an otherwise an impressive villain.
Come on dude, this ends with sunshine and rainbows and a gag bonus scene - it's hardly The Road.