Centipede

Centipede is the shooting game Atari built to be played with a trackball, and the control choice is why it worked. You aim with your whole hand rather than with a joystick, which made it the first arcade shooter that felt equally playable to women and men - and its designer, Dona Bailey, was the only woman on Atari's coin-op team.

The playfield is a field of mushrooms that you can shoot away one at a time. A centipede of twelve segments descends from the top, and every shot that kills a segment leaves a mushroom behind, so the field becomes denser as the round goes on. Kill a middle segment and the centipede splits into two independent ones, which is the game's real difficulty source. Around it: a spider that bounces diagonally, a flea that drops a column of mushrooms and a scorpion that poisons every mushroom it touches - a poisoned mushroom drives the centipede straight down through the field. The original reached arcades in 1981 alongside Defender and Galaga and became one of Atari's biggest coin-ops.

• ▸Trackball control - aim with your whole hand
• ▸A centipede that splits when shot in the middle
• ▸Poisoned mushrooms that send the centipede diving down
• ▸Spider, flea and scorpion, each with its own rule