Most of us are familiar with the classic Superman story: Superman, or Kal-el, is essentially an alien sent to earth as a baby by his parents to escape the impending doom falling on his home planet of Krypton. Found by the Kent family and raised as their son on earth, he later becomes a reporter at the Daily Planet, dons the suit and cape when needed and saves his reporter girlfriend Lois Lane again and again and again from various baddies.
"Man of Steel" endeavors to give more depth to Superman cannon. Superman isn't just sent away because of an unstable Krypton; Natural birth is illegal in Kryptonian society and his parents decided to break the law and have their own child without genetic manipulation. Kal-el’s life on earth is a dimmer one than in previous incarnations of the story. He has the same social problems that every human faces with friends and family (with the additional complication of having super powers). As an adult he wanders around for a long time working here and there until he happens upon a crashed Kryptonian ship that helps him find out his true identity. He also bumps into Lois Lane, saves her and thus their repetitive relationship is born.
But all is not well: The evil General Zod and his minions, the leaders of government rebellion on Krypton, have escaped exile from the depths of space and have plans to terraform the planet, which essentially means everyone on earth will die.
This looks like a job for…well you know.
"Man of Steel" has a strong central theme of morality being something we should all strive for and have the freedom to pursue.
The planet Krypton used to have a thriving culture that sought to explore the galaxy, but over time they lost sight of their goal. "Artificial population control" was established where every child was bred for a specific purpose. In contrast Jor-el and his wife wanted their son to be able to make his own choices. "What if a child dreamed of becoming something other than what society had intended for him…what if a child aspired to something greater," Jor-el asks. They have Kal-el in secret which some consider heresy: Krypton's first natural birth in centuries. Jor-el believes that Kal-el can be a symbol of hope, and can encourage every person to be a force for good.
Zod asks Jor-el to join him in his government take over, but Jor-el says that Zod has "taken up the sword against his own people" and that he will not join him in deciding who lives and who dies.
Kal-el also has a strong moral compass. He doesn't want to kill anyone even when the baddies are dealing out violence and threatening the ones he loves (although that doesn't mean he hesitates to pummel Zod's face when the General threatens Kal-el's adoptive mother). In the end Kal-el has to make the choice to end things or watch innocents die, and the remorse of taking another life is clearly evident.
In stark contrast Zod and his cohorts believe that a sense of morality is a disadvantage that they have evolved beyond.
“Man of Steel” earns it PG-13 rating from a handful of profanities and euphemisms, along with some minor sexual content that includes Superman and Lois sharing a kiss, and a few cleavage revealing tops worn by some. There is also a baby Kal-el in his birthday suit.
The violence is intense but rarely bloody. Jor-el gives Zod a nasty scar, after which Zod murders Jor-el. Krypton's core collapses killing all it's inhabitants including Kal-el's mother (a scene that is more poignant than violent).