Parallax (video game)  Parallax is a shoot 'em up video game developed by British company Sensible Software for the Commodore 64. It was released in 1986 by Ocean Software in Europe and Mindscape in North America. The game was named after its primary graphical feature, parallax scrolling, which gives the illusion of depth to side-scrolling video games. On release, reviews praised the game's mix of traditional side-scrolling action and adventure game-inspired puzzles. On a routine exploratory mission, five astronauts discover a friendly-seeming planet run by an artificial intelligence. The inhabitants drop their pretense of friendship after the astronauts uncover a plan to invade Earth. Four of the astronauts are captured, and the player takes control of the fifth, who must free his companions and stop the invasion. Gameplay is split between two modes. The main part of the game is a side-scrolling shoot 'em up aboard a spaceship. The player scores points by destroying enemy ships and turrets. At hangars, the player can land and exit the spaceship. In this action-adventure mode, the player drugs enemy scientists and retrieves keycards to unlock the password to advance to the next of five zones. The first scientist drugged in each zone also counts as a rescued astronaut. Once the password is unlocked in the fifth zone, the computer controlling the invasion shuts down, and the player wins. "Parallax" was Sensible Software's first game. It was designed after signing an agreement with publisher Ocean Software; Ocean was the first publisher Sensible approached. The founders, programmer Chris Yates and artist Jon Hare were 19 years old at the time. Yates came up with the initial concept of a shoot 'em up game where players could fly above and below platforms. Hare designed the levels and graphics, and Yates added additional effects, such as sliding walls. The puzzle elements were planned to be more complex, but the Commodore 64's limited memory did not allow it. The ending of the game, which simply outputs "System Off", was all they could fit in the remaining memory. Programming the game took six months, and it was released in October 1986. The game's score was inspired by Jean-Michel Jarre's album "Rendez-Vous", which composer Martin Galway had been listening to during development. Contemporary reviews were positive and highlighted "Parallax"s combination of shoot 'em up action and adventure-inspired puzzles. "Zzap!64" rated the game 93/100 and called it "a neat mix between shoot em up and an arcade adventure, with a few other things thrown in for good measure".