A game by Atari for the arcade, originally released in 1981.
Atari’s Centipede was one of the most iconic games of early 80’s arcade gaming. In this era, an arcade machine’s physical design and attract mode essentially played the part of the carnival barker, offering hints as to the amazing things that lay beyond the opaque curtain (“Step right up! See the amazing Centipede! Cut it in half, and it just keeps coming! Only 25 cents, folks!”).
Centipede lured players in with its amazing cabinet art, unique visuals and audio, and its use of a trackball as its primary control input – one of the first arcade games to do this. The unique mechanics, environmental interaction, visual progression indicators, and tension-driven gameplay kept players coming back to sustain the centipede on its diet of precious quarters.

As is typical of arcade game design, the game starts out slow and escalates very quickly, offering a balance of engaging gameplay and frequent death, tempting the player to drop in another coin when his stock of lives is depleted. The player character sits at the lower end of a mushroom field, and the player is able to move around in a confined area at the bottom of the screen and shoot upward. At the top of the screen, your multi-legged foe moves back and forth, dropping one level downward and reversing direction when it touches a mushroom or the edge of the screen, steadily descending on your position.

You must fire upward at the centipede, but hitting it in the middle causes one segment to be destroyed – and replaced by a mushroom – while the centipede splits at that point, sending one part onward and the other part backward, making it an even tougher target. For each section of the centipede you destroy, a new mushroom is added to the playfield. And the more mushrooms there are, the faster the centipede is able to move downward.

You are able to shoot the mushrooms as well, knocking away chunks of the mushrooms similarly to how the shields are destroyed in Space Invaders, with 4 shots destroying a mushroom completely. This environmental interaction is more than just a neat effect, however, as it allows you to manipulate the path of your enemy.

By destroying mushrooms completely, the centipede’s descent is slowed, but you can also use the arrangement of mushrooms to speed up its descent. A great strategy for quickly destroying a centipede is to get it trapped in a vertical row of mushrooms, forcing it to drop straight down while you blast away at its segments.

As the game progresses, things become more chaotic. Instead of levels starting with a single centipede, the centipede emerges with a number of individual single-unit segments running around on their own, making them tougher to hit. Additionally, a spider often appears at the bottom of the screen, moving around erratically in your play area, forcing you to dodge it – or shoot it for a score bonus – while attempting to focus on the descending centipede.

The closer the centipede gets to the bottom of the screen, the more dangerous it becomes, since you must work to dodge it and shoot it, and any mushrooms that are left within the player’s bounding box will cause the centipede to drop even faster. However, if you clear out too many mushrooms in this area, the game will spawn a flea that drops down from the top of the screen, adding mushrooms to the playfield as it falls. Flea drops become more frequent in later levels, and spiders can destroy mushrooms along the bottom of the screen, forcing more frequent drops as well.

There is also a scorpion enemy that appears in the upper section of the playfield and poisons any mushroom it touches. If you are not able to destroy these poisonous fungi before the centipede reaches them, you are in for some real trouble. When the centipede touches a poisoned mushroom, it drops straight down to the bottom of the screen. Upon touching the bottom, it starts climbing back upward in reverse, eventually reaching the top of your bounding box and moving downward again. If you are killed, any poisonous mushrooms remaining are turned back into regular mushrooms, and any partially destroyed mushrooms are restored as well.

Interestingly, all of the mushrooms in the playfield carry over from one level to the next, giving the player a bit of control over his fate from one wave to another, as the playfield changes based on his actions. While the game’s rules and enemy behaviors are certainly enough to keep the game interesting, the player’s ability to alter the environment in a persistent manner has a dramatic impact on how the game is played.

Furthermore, level progression is indicated visually, with the colors of enemies, mushrooms, and even the player character changing in each new area. Today, a new color scheme may seem like an insignificant reward for the player’s progress, but it is a clear indicator of how far you have made it in the game. Given the nature of arcades, which were just as much about playing games as they were about watching others play, you could tell when you were watching a master Centipede player at work merely by looking at the colors on the screen… and perhaps tempting you to give it a try yourself.

Centipede’s core gameplay is driven by a slow escalation of tension, which is supported by its audio design. A steady beat plays in the background as the centipede descends, and there are separate audio cues as each different enemy enters the screen. The dive bombing flea is given the sound of a falling bomb, the scorpion’s poisonous infestation is accompanied by a warbling noise, and the chaotically-moving spider is matched up with a loud cacophonic sound.

When you’re whipping around the screen like mad and trying to nail those last few centipede segments while pinching your fingers on the trackball’s edge, the sound of a spider entering the playfield serves only to increase your panic response.

Another interesting mechanic is that is that the player character is only able to fire one shot at a time, and holding the button down allows for continuous shooting. What this means in terms of gameplay is that the centipede is harder to hit when it’s further away, and missed shots leave you temporarily defenseless (adding a bit more tension). The most effective method of defeating the centipede is also the most dangerous: let it get close to you and fire as quickly as possible.

The player must remain constantly aware of multiple vastly different threats while considering his firing rate and managing the continued addition of mushrooms to the playfield. Players earn 1UPs every 10,000, 12,000, 15,000, or 20,000 points (based on the machine’s switch settings), offering a reward for vigilant players and offering the chance at further progression.

Centipede was developed by Atari, the developer behind a number formative arcade titles from the 1970's and early 1980's, including Pong, Breakout, Asteroids, Lunar Lander, Missile Command, Battlezone, Tempest, Gravitar, and Star Wars. The company also created a series of home computers and video game consoles, along with games for those systems.