Alien 3 for the Sega Master System.  The Xenomorph are fast, spit acid, and are right behind YOU! Can't see very far ahead in these air ducts. Hard to breathe. Face-huggers can be anywhere. Must find the Mother Alien. The closer you get, the more Aliens you find... better not have them find you first! Just keep telling yourself, "this isn't really happening... it's only a game!"