Asteroids

Asteroids is a space shooter first released in arcades in November, 1979 by Atari. It was later ported to numerous home computers and game consoles. In the game, players control a space ship caught in an asteroid belt with the goal of destroying all the asteroids (along with flying saucers) that are there. Asteroids was a phenomenal success, selling over 70,000 arcade cabinets and numerous copies of the various home versions. It was also very influentual and inspired numerous clones and other games which borrowed gameplay elements.

In Asteroids, players control a triangular ship with the goal of destroying all of the asteroids on the screen. The ship is capable of firing forward, rotating left and right, and thrusting forward. Being in space, the ship has inertia — it will continue to travel in the present direction and speed until the player thrusts in a different direction. As a last resort, the ship is also equipped with hyperspace ability; when activated, the ship will dissapear from the present location and randomly appear at another. While this can be used to escape a dangerous situation, it also has a risk that the ship will reappear in the middle of an asteroid and be destroyed.

Each level begins with several asteroids floating randomly around the screen. When a large asteroid is shot, it will break into several smaller pieces. Eventually the asteroid pieces become small enough that they can be destroyed when shot. After all asteroids are destroyed, the next, more difficult level begins. From time to time, a flying saucer will appear on the screen. There are two types, a large saucer that has poor aim when firing at the player, and later in the game a smaller one which is more accurate. The saucers can be shot for bonus points, or may also leave the screen on their own if left alone.

The original arcade version of Asteroids used a black & white vector monitor. This provided very sharp graphics with geometric outlines used for all of the objects. Since the home systems the game was ported to did not have vector monitors, the graphics were changed according to each system's capabilities. Color was added, the asteroids were solid instead of just outlines, and for some versions (such as the Atari 7800) textures were added to the asteroid graphics.