There are some arguments about what exactly a sequel should be. Some will tell you that it’s to be the same as the first movie but with improvements made all around (because we know how often that happens) and some will say that the point is to change the formula and create something new out of previous concepts. I tend to not care as long as I get another film that is worth watching and doesn’t just reuse the formula until it’s boring. Franchises have done this time and time again and I’m sick of it. “Aliens” takes what Ridley Scott did with “Alien” and does almost exactly what it says on the tin, makes the enemy plural.