Asteroids, one of the most memorable space games, was released by Atari in November 1979, and can be summed up as a game of cleaning up the screen.
Player controls a ship in the middle of a field of asteroids and shoots large, randomly moving boulders to pieces, and continues shooting the pieces to even smaller pieces, while avoiding collision.
When all the fragments have been destroyed, player enters the next field, where the asteroids are now moving faster.
The ship possesses inertia, and when the asteroids blow up, they send pieces in many directions at different velocities.
It is the first video game with a developed physics system.
There was yet another feature that made a breakthrough with the Asteroids.
Usually, in earlier games graphics consisted of little groups of pixels.
Here Atari introduced laser-sharp, angular game graphics with their "Quadra-Scan" vector monitor.
Today vector graphics is no big deal, but at the time, it was very futuristic, and added a new layer of realism to video games.
Asteroids did not just pop out from nowhere.
Its roots go back to the very beginning of video gaming.
Its immediate precursor was an arcade game entitled Space Wars, where the wedge-shaped little spaceship already appeared.
Space Wars in turn was direct offspring of the truly ancient computer game Spacewar, a program written in 1962 for PDP-1 machine at the Massachusetts Institute of Technology.
Because Spacewar was popular among MIT students, there had been attempts to turn it into arcade game.
Different spinoffs include such titles as Computer Space and Galaxy Game.
They all failed to attract the public, who found the games confusing and the controls cumbersome.
These space games, appearing years before the advent of Pong, were simply too ahead of their time.
Asteroids, however, succeeded to break into mainstream, and became a wildly successful hit game.
As a mark of its pedigree, it has a button, which, when pressed sends the ship to a random location of the screen.
This "Hyperspace" feature was already in Spacewar.
Very soon after its release, Asteroids rose to the top, and ended the reign of Space Invaders, the previous emperor of arcades.
70 000 cabinets were sold worldwide.
Some came with extra large boxes to accommodate all the coins of Asteroids-hungry gamers.
Asteroids was making so much money, that together with the sales of VCS home consoles, Atari provided about third of all the revenues of its parent company, Warner Communications.
What are the reasons behind the success of Asteroids? It comes down to a winning combination of meticulously designed and tested gameplay and vector graphics.
The motions of the asteroids and the spaceship were executed with gracefulness never seen before in space games.
This helped to produce a strong sense of immersion, of being really inside the game, floating in space.
Player feels like a hero; there is a great sense of accomplishment in getting asteroids demolished, wave after wave.
Ultimately, Asteroids appeals to some deep instinct of tidying up the debris - and having fun while doing it.