Designed by Ed Logg and Dona Bailey, Centipede is a superfast fixed-screen shoot ’em up from the arcades of 1981.
You control a bullet-spitting head at the bottom and must shoot the Centipede as it trundles down the screen. Shooting any piece of the Centipede turns that segment into a mushroom. If the Centipede‘s head hits a mushroom it’ll turn around and move one place lower on the screen, so shooting the mushrooms can give you time and keep the Centipede higher up the screen.
When the Centipede reaches the bottom it can hit and kill you, so the game’s designers give you some leeway and allow you to move up and down within a small strip at the bottom of the screen. If you do manage to avoid the Centipede and it reaches the bottom, it will then stay in that portion of the screen until either you or it are dead.
Of course: completely eradicating the Centipede spawns a whole new level, a new, more difficult Centipede, and a colour change.
Centipede arcade cabinets were mostly fitted with a trackball, for fast, fluid, analogue control of the head. It was one of the first shooters to feature extremely fast gameplay and movement. A simple shooter from Atari, but pure and tough and influential.
More: Centipede on Wikipedia