Canvas Games: Part I - HTML5 Canvas - page 635

Our Game's Design
We are not going to assume that everyone who reads this chapter knows of or understands
Atari's classic arcade game Asteroids . So let's start by taking a peek at the Asteroids game-
play elements.
Asteroids ,designed byEdLoggandLyle Rains, wasreleased byAtari in1979.The game pit-
ted a lone triangular two-dimensional vector spaceship (the player ship) against screen after
screenofasteroidrocksthatneededtobedodgedanddestroyed.Everysooftenaspacesaucer
would enter the screen attempting to destroy the player ship.
All asteroids started the game as large rocks; when they were hit, they would split into two
medium-sizedrocks.Whenhitbyaplayermissile,thesemedium-sizedrockswouldthensplit
into two small rocks. The small rocks would simply be destroyed when hit. (Small was the
final size for all asteroids.)
When the player destroyed all the asteroids, a new screen of more and slightly faster asteroids
would appear. This went on until the player exhausted his three ships. At each 10,000-point
score mark, the player was awarded an extra ship.
All of the game objects moved (thrusting, rotating, and/or floating) freely across the entire
screen, which represented a slice of space as a flat plane. When an object went off the side of
the screen, it would reappear on the opposite side, in warp-like fashion.