One of the most striking things, for me, about this movie is that Arnold doesn't kill anyone--or at least it doesn't show him killing anyone. If you're a fan of the movies, you're aware of how much more violent Arnold's character is in the first movie. In 1991, this movie was the most expensive ever made ($52 million) and broke down all kinds of technological barriers. Having said that, the movie is chock full of bad language, rebellious youth, and stylized violence. Some teenagers will be able to relate to some of John Connor (Edward Furlong)'s frustrations as he's been shuffled around from foster parent to foster parent, has a clinically crazy mother, skips school, and steals money. Of course, the T-100 (Schwarzenegger) is a cold, remorseless, robot, incapable of showing any type of emotion that has been re-programmed by a futuristic John Connor to save himself as a teenager.
Despite being violet and having a ton of bad language, there's a lot of positive messages one can take aware from the movie. One is that "you can't kill people". John tries throughout the duration of the movie to explain this to the terminator, a concept that he's capable of following but is incapable of comprehending. Another is the very strong anti-war/nuclear weapons message and that if humans are going to wage war on another, they need to be in control. Because the machines are emotionless, they're incapable of making moral judgements, something that the human race should be conscientious of. A typical Cameron film, there are also elements of anti-establishment within the picture.
I saw this movie at the age of 12 in the theaters with my dad and we both loved it. I think 12 year olds of today can enjoy it as well, if coached by a parent, and given maybe a little bit of help to understand the complexity of the undertones within the movie.