Space Invaders is a video game based on the novel of the documentary based on the well-known alien invasion of 1978, in which unending hordes of spaceships continually descended towards a single tank. It is widely considered to be an arcade classic, especially by people who long for a happier time when games could be made in five minutes by some kid in his bedroom. However, many have pointed out that those games suck when compared with modern classics like The Sims, Halo and Iraq: Suicide Mission. They are wrong.
Infinite aliens are attacking! Only you stand between them and the destruction of the Earth and the enslavement of the human race (or something). Since the President, in his infinite wisdom, has decided to send all the troops somewhere to fight some sort of evil boogie-man you have been given just a tank (with infinite ammo) and some floating arches with which to defend your planet. Luckily for you, all of the aliens are landing exactly where your tank is, and nowhere else. Also luckily, the aliens land very slowly, which gives you ample time to shoot them down.
Due to some unspecified mechanical failure, your tank can only move in two dimensions and can only fire directly upwards. Luckily, the aliens are two-dimensional and only exist in the same plane as your tank.  Your job is to move back and forwards firing lines of some sort of magic laser at the aliens thereby destroying them instantly leaving no trace of their existence. The aliens also fire stuff at you. Though at first the levitating arches protect you, these are soon destroyed leaving you virtually defenceless. You now must use your tank driving skills to dodge the alien weapons. Occasionally a flying saucer will fly across the upper portion of the screen to supply its troops with cheap ale and hot dogs. If you shoot it down you get points (and hot dogs). As you shoot down more and more aliens they begin to advance faster. It is usually thought that this is a deliberate tactic. General George S. Patton has said that it is a terrible tactic and suggested that the aliens aren't as clever as they look.
The game was one of the first to involve infinite levels of difficulty - i.e. the aliens just keep coming forever. It is not possible to 'win' the game, only delay the inevitable destruction of civilization. Your aim is not to stop the invasion but rather to delay it so that the rest of humanity can have a few more hours of TV and celebrity gossip.
Philosophers have noted that the unbeatability of Space Invaders mirrors the futility of human existence - no matter how long you survive you will always die in the end. However, in real life no one will record your highscore and there is no chance of replaying . Many go so far as to say that the game's true purpose is as a metaphor for nihilism and that if Nietzsche had made a video game instead of just going nuts it would have been like space invaders. Others, however, have suggested that the game is not negative and nihilistic but rather is a positive celebration of mankind's struggle against its own meaninglessness and the inevitability of death. Others have suggested that they are reading too much into a simple video game and that they should go get a real job.
It is often said (mostly by people who know very little about anything but are paid to sound as if they do) that Space Invaders defined a generation of young people with nothing better to do than play games all day. One thing we can say with certainty is that Space Invaders is a game that people played a lot.
Numerous conspiracy theorists and other associated nutcases have speculated that Space Invaders, and indeed all early video games, were created by the government in order to prepare the youth of the day for a life mindlessly pushing buttons in killer robot factories. However, this is almost certainly untrue.  Another popular theory is that the game was created by a race of highly intelligent aliens in order to subliminally convince the people of Earth that resistance is futile. Others believe the Jews did it. However, it is most likely that the game was made by some guy in order to make money.
For the most part, the concept of game is defending the planet from waves of aliens. However, some think the situation isn't this black-and-white. For instance, there are a wide variety of aliens, forgetting their differences and living in harmony. Maybe they came here to tell us to love one another and to respect others equally, but we reacted with the very distrust they were hoping to bring an end to! Many people have decided to embrace these so called "invaders" and accept them into our society, with equal respect and love. Others think that since these aliens are apparently hippies, that makes the game much more fun.
Space Invaders is universally regarded as an arcade classic like Pac Man, Tetris, Pong, Zork and Richard Nixon's Puzzle Challenge. It has spawned numerous spin-offs and quasi-legal imitations. Some of the most successful of these include:
- Alien Invaders From Beyond the Sun - This was essentially a direct copy of Space Invaders except that the aliens were a different colour. This led to a bitter legal battle that was eventually settled out of court. 
- Mohammed vs. the Infidels - In this game you play Mohammed who must drive all the infidels out of Mecca in order to establish the 'peace-loving' religion of Islam. Under Islam, it is forbidden to depict the prophet Mohammed. However, it was decided that a low-resolution image for illustration purposes constitutes fair use.
- Minuteman: Immigrant Invaders - The player must shoot Mexicans as they attempt to cross the border into America. 
- The Commies Are Comin - Produced by the U.S. Government, the player must kill as many evil Commies as possible. In contrast to all other Space Invaders-esque games, the Americans always win - even if you fail to kill any commies.
- Mason Blasters! - Produced by Alex Jones, it was used to divert attention away from their plans for world domination by telling people to kill fat old men who sit in wooden buildings all day and shake hands. The rights were later handed over to The Mafia to make Super Mario Brothers, another effective propaganda game made by a secret society.
- ^ They are from another universe, you see.
- ^ "Did you hear about Paris Hilton? Oh shit! Aliens!"
- ^ Unless you are a Hindu.
- ^ Big Brother has assured us.
- ^ Over a game of Space Invaders.
- ^ Very popular in Southern States.
- ^ Barbie Race and Ride holds the title to this day.