Centipede was an old arcade game released by Atari way back in 1980.
The story
It is always been said that Centipede was the first video game ever designed by a woman (Dona Bailey), although recent interviews with members of the original Centipede team have made it clear that Dona only played a minor role in the project.
Centipede has long been considered a true classic (no matter who actually designed the game), and it has inspired several sequels and computer clones, and been ported to several early console systems.
The game
In Centipede you are attempting to gain as many points as possible, by shooting down your assorted enemies, and by destroying all the segments of the roaming "centipede". You control a little "gun" that is confined to the bottom fifth of a mushroom littered screen. The centipede moves from side to side across the screen, reversing direction (and moving closer towards the bottom), every time it encounters an obstacle. It is composed of segments that must be shot, and it will break into smaller centipedes as you shoot away individual segments (which become mushroom obstacles). Upon reaching the bottom of the screen the centipede begins to work its way back up, and it is reinforced by a second centipede head, which enters at the top of the players area.
On the first level the centipede begins as a single unit (until you shoot it up a bit that is), on the second level it begins in two parts, the third level in three parts, and so on until all the segments start independently of each other.
The centipede is not the only enemy that you must deal with. The spider bounces around in the player's movement zone (but is semi-useful because it destroys the mushrooms that litter the playfield and get in the way). The spider is rather easy to kill, but another one will soon take its place. The flea serves to add mushrooms to the screen. Whenever the screen contains less than a magic number of mushrooms, the flea will drop from the top of the screen leaving a vertical array of mushrooms behind. I myself have found the flea to be the most difficult enemy, but other people seem to have no problem with it. As a matter of fact one of the high score techniques is to trap the centipede and shoot fleas forever (the centipede can be trapped in the bottom section by carefully shooting away sections of it, until it is enclosed in a box). Using that technique has been declared illegal for purposes of achieving the world record score (according to Twin Galaxies, the people who track the record scores on video games).
The scorpion is particularly dangerous, not because it attacks the player, but because it turns regular mushrooms into poisonous mushrooms. When the centipede encounters one of these it will dive for the bottom of the screen quickly, and then head back up (which can be tough to avoid).
You get a bonus life for every 12,000 points. This means that a skilled player can play the game forever, gaining a bonus life every few levels. This is possible because the levels do not ramp up in difficulty forever). So you can basically play endlessly once you reach a certain level of skill. This makes beating the world record score a simple matter of endurance.
The Machine
Centipede came in three different from factors, upright, cabaret, and a cocktail table. The uprights were by far the most common. All of them can be converted to Millipede with only minor effort. They all have control panels with a trackball, although the upright version uses a larger ball than the other ones do. All of the trackballs are prone to wear and tear, but replacement parts are readily available.
The upright was in a white cabinet that was similar in construction to the Asteroids cabinet. The game featured ornate painted sideart of a truly evil looking green bug, while the monitor bezel and marquee basically copied the same picture, but from a different angle.
The cabaret was an ugly looking little thing, with woodgrained sides, and a nameplate down by the coin box (I think all cabaret style games are ugly, so I might be biased in judging this machines appearance).
The cocktail version is black and woodgrained, as has two control panels. The only graphics on this one are a pair of Centipede logos underneath the glass (the same design is also repeated on the control panels.
Where to play
Centipede was so popular that you may actually be able to find a real machine to play on (my local arcade had one last time I checked). If you wish to play at home you can try the Atari 2600 cartridge, or any of the various ports or clones. You can even use the MAME emulator, but it doesn't control correctly unless you have a trackball.
If you want to add this to your arcade game collection, then you better have some money, as Centipede is a very overpriced title (think $700+ for an upright in "fair" condition). I say pass on this one, as you could purchase two or three very nice games for the price of a single Centipede in average condition.