They brought back Hicks... No, not just that opening video, which is a great excuse for a cameo. Instead, they bring him back under the premise that he never left the Sulaco in the first place. He shows up as a "hooded figure" who joins the hero to fight Weyland-Yutani.
Fight them, because apparently they were up to no good experimenting on the xenos. Oh wait, before I go too far, I should mention that they actually reference Hicks's corpse from Alien 3. The explanation they give? "Oh, that's a story for a different time..." fuuuuuuuuuuccccccckkkk you That's not just a lame attempt at fan-service but rather just sloppy, lazy storytelling.
So yeah, apparently the story ends up being that the "human" Michael Weyland shows up personally to try to experiment on the xenos. The "twist" at the end though is when Hicks puts a bullet in Weyland's head it turns out that he's an android too.
I really thought the scaling back of an explosion "the size of Nebraska" so as to allow Hadley's Hope to survive was going to be the extent they were stretching the story. Instead, that was probably the smallest stretch they ended up making in this game.