Space Invaders

Space Invaders is quite simply the most influential
video-game of all time. A single player moves an armed
'laser base' left or right along the bottom of the 
screen and shoots the endless waves of aliens marching 
relentlessly down the screen towards earth.

There are four buildings (shields) at the bottom of 
the screen that the player can hide behind, but these
will eventually be destroyed by either enemy missiles
or by direct contact with the invaders themselves. 
The player's shots will also destroy the shields.

The aliens' descent quickens as they are eliminated, 
making them harder to hit. A flying saucer will fly 
across the top of the screen at regular intervals 
and can be shot to earn extra points.

Developed by Taito/Midway