Each time you turn on SPACE INVADERS you will be at war with enemies from space who are threatening the earth. Your objective is to destroy these invaders by firing your "laser cannon." You must wipe out the invaders either before they reach the earth (bottom of the screen), or before they hit you three times with their "laser bombs."
--From the Atari 2600 Space Invaders instruction manual.
I know, it's not exactly the greatest story ever told. And the best part is, you don't even get to save the day in the end. They just keep sending wave after wave, until they finally get you.
One of the true classics of video gaming, and possibly the first coin-op video game ever to be ported to a home system. Space Invaders spawned countless sequels and knock-offs due to its insane popularity both at the arcade and in the home.
You control a tiny little cannon and must defend Earth from the hordes of aliens dropping down toward you. Not only can they shoot back, but if you let even one space invader touch the ground, it's all over, everybody dies, the end, goodbye. Your only protection consists of three floating shields which will be pecked away by enemy fire, that is if you don't shoot them first yourself, just to get them out of your way.