I personally liked this movie. It had tons of action. The trick to enjoying movies is coming with the right mindset. Don't expect a fluttering drama out of this one.
On to the appropriateness:
Sex: Kissing, references.
Violence: All over the place, characters die in many different ways including getting run over by a tank, impaled by a mounted elephant horn, blood sucked out by a vampire, shot, stabbed, crushed by a collapsing building, and aging at 10 years a second. However despite some of the gruesomeness in these they are all bloodless (With the exception of the vampire one, you get to see her bloody mouth afterward). Also slightly video game like are the fact that with two exceptions, you do not get to see corpses.
Substance abuse: Alcochol is consumed mildly
Social Behavior: The LXG are ultimately in it for good, even though they use shoot first methods.