The movie promotes the idea of different cultures coming together for a common cause; in general, characters tend to face fears and go up against terrible odds for the greater good. The movie's most interesting idea is "the drift," in which two people must join minds and sync up in order to control the giant robots together; it's the ultimate metaphor for teamwork.
The many fight scenes between the giant robots and giant monsters have lots of punching, smashing, extremely loud destruction of property (including the near-complete annihilation of cities), and collateral loss of life, but they're mostly bloodless. One important (albeit minor) character dies. In one sequence, a character has trouble with "the drift," and viewers see some somewhat scary flashbacks to her as a young girl, chased and terrified by monsters. Fights between pilots being tested for compatibility, plus another fist fight. Constant peril. A character suffers nosebleeds.
The main character (a man) is shown shirtless more than once. In one scene, a female character breathlessly admires him. The male and female leads banter, fight, and bond over the course of the movie in a mostly non-sexual way. At the end, they share an almost kiss (but not quite).
Language includes a couple of uses of "s--t," plus "bitch" (or "son of a bitch"), "ass," "bastard," "goddamn," "hell," "damn," "oh my God," and "for Christ's sake."
During the prologue, there's a sequence in which the Jaegers become popular as cultural icons/consumer objects. (Toys from this movie could become just as popular.)