Asteroids

An Atari Asteroids clone written in JavaScript

Controls

UP    : accelerate the ship
LEFT  : rotate the ship left
RIGHT : rotate the ship right
DOWN  : jump into hyperspace (teleport to random location)
SPACE : shoot

Limits

• Ships can shoot up to 3 times per second.
• Ships can jump into hyperspace up to 1 time per 3 seconds.

Gameplay

• The game begins with three lives.
• Lives are lost when the ship collides with enemy bodies or bullets.
• The ship reappears in the center of the screen when a life is lost.
• Levels are completed when all enemies are destroyed.
• Asteroids, aliens, and ships wrap around the screen.
• Bullets do not wrap around the screen.
• Large asteroids break up into three medium asteroids.
• Medium asteroids break up into three small asteroids.
• Smaller asteroids move more quickly.
• Two aliens appear after the first level.
• The large alien shoots randomly.
• The small alien shoots toward the ship, with increasing accuracy at each level.

Points

Large asteroid      20
Medium asteroid     50
Small asteroid      100
Large alien         200
Small alien         1000

Bonus

One life is earned every 10,000 points.

Notes

• The aliens have developed special bullets that do not harm other aliens or asteroids.
• Aliens have a 50% chance of firing every 3 seconds.
• Ship bullets and alien bullets destroy each other.
• Aliens can die by kamikaze attacks.