Where Ridley Scott's Alien was a creeping horror, for the sequel, director James Cameron swapped genres, delivering an all-guns-blazing action movie. That's not to say that it's unsophisticated; Cameron was inspired by America's experience in the Vietnam War in depicting how the gung-ho Space Marines are undone by a technologically-inferior enemy.
Heroine Ripley's character was fleshed out too, with the blue-collar worker of the first film recast as a surrogate mother to xenomorph survivor Newt – in Cameron's director's cut, he added further layers with the revelation that after 57 years in stasis, she missed her daughter's entire life.