How to play Asteroids online
- Rotate: left and right arrows; thrust: up arrow; defensive move (shields, hyperspace or flip over, whichever option is chosen): down arrow
- Fire: Z
- Start: Enter; Pause: P
- Keypad: K opens the on-screen keypad, or press the digits directly. AtariProtos says keys 1 and 3 switch between fast and slow asteroids; other functions are undocumented.
Gameplay
The port follows the Atari 8-bit computer version: shoot the big rocks, which split into smaller ones, and clear the screen to move on. According to AtariProtos it supports up to four players at once in Melee, Co-op or Team mode, each playable as Patrol (shots pass through other ships) or Combat (players can shoot each other for points).
Why it was never released
Atari planned Asteroids as a launch title for October 1982 and had a label and box made; the surviving cartridge is dated 12 August 1982 and described as a very late work in progress. The problem was the controller: the 5200 stick does not spring back to centre, so the ship keeps spinning and thrusts or warps by accident. Atari even built a boxy “Asteroids Controller” with arcade-style buttons, but the game was still shelved. The 5200 programmer is not known for certain; Tod Frye wrote the computer version.

