Easter egg: In the "20th Anniversary Edition" (the same one that is part of "The Alien Legacy Collection"), go to the "Extra Features" submenu, on the first screen keep moving the cursor downward until you go past "Main Menu" and highlight an acid hole on the bottom and press the confirmation button to select it. You'll be brought to a menu meant to look like a message science officer Ash is sending to the company detailing the life cycle stages of the alien creature.
Easter egg: Go to Special Features. Go to the next screen via the More option. Hit up arrow until a ball becomes highlighted. Select the ball and you will see a picture of the crew and a girl give a long scream.