Millipede is the sequel to Atari's Centipede. Designed by Ed Logg, it takes some of the familiar elements from Centipede and changes them graphically, while adding completely new elements, including new enemies and a new weapon. The arcade game features a trackball controller for precise movement.
Gameplay is similar to the Centipede's: Players control the Archer, a shooter bounded by the bottom third of the screen. Only one bullet can be on-screen at a time. If struck once by any enemy or bullet, the Archer is destroyed. The game field is populated with mushrooms which serve as obstacles, minor points when destroyed, and can be used by enemy and the player to block or accelerate movement of the main enemy, the millipede.
Once all of a millipede is destroyed, all mushrooms move down one step toward the player field, and the next round starts, usually marked by a new swarm of enemies and the color of the playfield changing.
The Millipede is the focus of the game, and moves predictably. Shooting it in one of its middle sections will spawn two millipedes with the remaining body length. The millipede will divide in this way each time it is shot, unless the head or tail segments are shot. When the millipede reaches the bottom, in addition to spawning new heads, the body will break up and plague the Archer's playfield.
Spiders function as in Centipede, consuming mushrooms and jumping erratically, mostly within the player zone. The player gets a higher score if the spider is shot when it is very near the Archer. Should a spider eat many mushrooms, a Bee (the equivalent of the Flea from Centipede) is likely to spawn.
Bees fly in a straight line from the top of the screen down to the bottom, spawning mushrooms in its wake. It can be killed by multiple shots, and is spawned when there are few if any mushrooms. This requirement can cause many Bees to be spawned in succession as they try to repopulate the playing field with mushrooms.
Dragonflies act similarly to the Bee, spawning mushrooms. Its flight pattern is that of a wave, making it harder to hit. Unlike the Bee, they only have a single hit point. They also spawn more mushrooms on average than Bees do.
The Earwig poisons mushrooms. It starts near the top of the screen, moving left or right, and any mushroom it runs across becomes poisoned. A poisoned mushroom is worth more points, but also sends the millipede directly down the screen. The Earwig is one of the top scoring targets in the game.
Beetles are slow, but when they run over mushrooms they actually transform them into flowers, which are indestructible.The Beetle also moves in a 'U' shaped attack pattern, entering the screen at a side, then moving down near the bottom, then ascending before it leaves, threatening the Archer with collision and converting mushrooms into impenetrable obstacles. Killing a Beetle makes mushrooms move down one row. All flowers become mushrooms again when a life is lost.
Mosquitos fly down at a 45 degree angle. When killed, all mushrooms move up one row, clearing them away from the player zone. This may destroy DDT bombs and prompt Bee spawning.
Beneficial or benign Creatures and Objects
The mushroom is the mainstay of the game. It has multiple hit points and can block the Archer from moving. It can also help to corral millipedes, making them easier to hit. Any mushroom partially destroyed is restored when killed, resulting in a small bonus.
A poisoned mushroom is one touched by an Earwig. It is worth more points when destroyed, and is restored to normal upon death.
Flowers are Beetle-converted mushrooms, and are indestructible. They revert to regular mushrooms and give points similar to the way partially destroyed mushrooms do.
DDT Bombs spawn at the top of the screen as mushrooms do when a Beetle or Millipede is fully killed. Shooting the bomb results in a cloud of lateral smoke in both directions. Any enemy caught in the cloud is instantly killed and scored.
Inchworms are creatures that are beneficial if shot. Shooting one causes the game to slow down for a short period of time, making targeting enemies much easier.
- Millipede body segment: 10 points
- Millipede head: 100 pts.
- Spider (long distance): 300 pts.
- Spider (mid-distance): 600 pts.
- Spider (short distance): 900 pts.
- Spider (point blank): 1200 pts.
- Spider (with DDT Bomb): 1800 pts.
- Beetle: 300 pts.
- Mosquito: 400 pts.
- Bee: 200 pts.
- Inchworm: 100 pts.
- DDT Bomb: 800 pts.
- Dragonfly: 500 pts.
- Earwig: 1000 pts.
- Mushroom: 1 pt.
- Mushroom regeneration: 5 pts. per poisoned, partly destroyed, or enflowered mushroom upon death
Swarms, which happen every 4th round, give bonus points for every successive insect obliterated. They are made up of different insects depending on the round, and can net a large bonus if enough are shot.
Every five rounds, mushrooms regenerate on their own. They obey the laws laid down by mathematician John Horton Conway in his Game of Life, with some special exceptions: DDT bombs poisoning neighboring mushrooms (naturally), and mushrooms adjacent to poisoned mushrooms dying off. Flowers count as mushrooms to determine if they generate or kill off others, or kill off themselves.
There are spider swarm waves which have as many as eight spiders on the screen at once (instead of the usual two) and waves where mushrooms move down much quicker than normal, making it much harder to maneuver and control the environment.