Newt’s blanket
Newt crawled through the air ducts of Hadley’s Hope colony to avoid getting cocooned by the xenomorphs. Apparently, a piece of her blanket got stuck on a ceiling fan. The spinning rag even shows up on your motion tracker.
Weyland-Yutani tricycle
In the special edition of Aliens, a kid rides a tricycle down the corridors of Hadley’s Hope colony. I found the tricycle, and it really bummed me out.
Legendary weapons
The Sulaco‘s crew is long gone, but some of their weapons remain scattered throughout the ship and on Hadley’s Hope. Keen-eyed marines may find and pick up Hicks’ shotgun, Gorman’s pistol, Hudson’s pulse rifle, Vasquez’s pistol and smart gun (pictured), and Frost’s flamethrower.
Casey’s head
Newt lost her doll, Casey, in the sewers of Hadley’s Hope colony when a xenomorph grabbed her. I’m happy to report that Casey’s head is fine, even though her new expression says otherwise.
Power loader battle
The Caterpillar P-5000 Work Loader comes in handy when you need to move heavy crates, load missiles into dropships, or smack large alien beasts in the face. Ripley used a power loader to fight the xenomorph queen in Aliens, and Corporal Winters (the marine you play as in Aliens: Colonial Marines) does the same to wrestle a nasty xeno code-named “Raven” into submission.
Doughnut
This reference is a bit far-fetched, but bear with me. A box of donuts sits on a rock in mission seven. Shooting it summons a giant doughnut that rolls down a hill and falls into a lava pit. It could be a random Easter egg, but you can see a half-eaten, wet donut for a split second in Aliens when the marines enter Hadley’s Hope (before the xenomorphs show up).