Alien is a 1984 top-down adventure video game developed by Concept Software and published by Argus Press Software for the Commodore 64 and ZX Spectrum. It is based on the film of the same name. A version for the Amstrad CPC was also released in 1985.
The entire game takes place aboard the Nostromo, which is viewed from a top-down perspective displaying the layout of the vessel. At the beginning of each game, the entire crew is alive, and one of them is randomly selected as the one carrying the Alien and another is selected to be an android. The Alien will be born shortly after the beginning of the game, killing the crew member. After this, the Alien hides away, quickly matures and begins to wander the ship, trying to kill the remaining crew. The goal of the game is to kill the Alien.
Any remaining crew members may be controlled by the player. It is possible to attack and kill the Alien directly using various weapons around the ship. Another alternative is to scuttle the ship with the Alien on board and escape in the shuttle, but, as in the film, the entire crew cannot fit in the shuttle. Eventually, the android crew member will try to aid the Alien. However, this can be prevented if the player can figure out who the android is, and they can be placed cryo before the player loses control of them. At the end of the game, the player is given a percentage score which is based on several factors including how many crew members are alive, whether the Nostromo self-destructed and if the player successfully identified and contained the android crew member.