Space Invaders

Space Invaders is a game in which the player controls a laser cannon by moving it horizontally across the bottom of the screen and shooting at descending aliens. The aim is to defeat five rows of eleven aliens - in some versions there are different numbers - that move horizontally back and forth across the screen as they move towards the bottom of the screen. The player defeats an alien and earns points by shooting it with the laser cannon. The more aliens are defeated, the faster both the aliens' movements and the game's music become.