Space Invaders

Atari 5200 version of Space Invaders

Space Invaders is a action/shooter game first released by Taito in 1978 and later ported to numerous computers and game consoles. One of the most successful and influental games of the era, the goal is to earn as many points as possible by shooting all of the alien invaders before they can land. Space Invaders is also the first arcade game to be licensed for release on a home system (initially for the Atari 2600 with many other ports to follow).

Players control a laser canon which can move horizontally along the bottom of the screen. Descending from the top of the screen are multiple rows of alien invaders; they move back and forth and each time the end of the screen is reached reverse direction and drop down one level. If they invaders make it all the way to the ground, the game is over so players to shoot all of the aliens before they land. Initially, the invaders start each level moving slowly; as the aliens are eliminated, their speed increases with the final invader moving the quickest. From time to time, a flying saucer appears and flies across the top of the screen; shooting the saucer earns a random amount of bonus points. The saucer is harmless and doesn't attack the player or otherwise get in the way.

The player's laser canon has some protection in the form of shields which are just above it (the arcade version has 4 shields and the number varies in some other versions of the game). The shields block both the invaders and the player's shots; each time a shield is shot, part of it is destroyed so over time they will provide less protection. If the invaders are low enough, the shields will disappear entirely. Players begin the game with a limited number of of laser canons; if a canon is hit by the invader's fire, it is lost. The game ends when players have no more canons in reserve.