Alien: Isolation was the scariest thing we saw at this years E3, and when the game launches youll be able to experience those scares with the films original cast — provided you pre-order the game. While the main game is set years after the first Alien film, publisher Sega has just announced two downloadable missions for Isolation, which let you relive scenes from the 1979 Ridley Scott classic. Those missions will include the voice acting talents of Sigourney Weaver as Ripley, Tom Skerritt as Dallas, Veronica Cartwright as Lambert, and more, several of whom will be playable characters.