A mothering instinct/motherly love drives both Ripley and the queen alien. Technology doesn't always guarantee sueriority in combat, as shown by gung-ho Marines charging into tunnels with high-powered guns only to get shredded to pieces by hordes of an enemy that keeps on coming -- director James Cameron's metaphor for the Vietnam War.
Mostly in quick flashes, but still severe, as human characters are splashed with acid, torched with fire, or have little aliens bursting out of them. One man is literally torn in half, with the qualifier that "he" is an android, not human, with beige-colored blood and viscera. Gunfire, bombs, and flamethrowers are directed at the aliens. Much of the violence and lethal danger is threatened against a small child.
Indistinct glimpses of pin-up pictures in a locker room. Some mildly suggestive banter between co-ed Marines.
"F--k" and "a--hole" in soldierly banter and anger.