Your ship is trapped in an asteroid field, and the only way to survive is to keep shooting! Shooting the big asteroids that threaten to destroy your ship isn't enough, however; they just break up into smaller asteroids, each just as deadly. You must keep firing until every asteroid is nothing more than space dust. Then, just when you think it's safe, more asteroids appear! There seems to be no hope of your ship getting through this alive, but maybe you can last long enough to reach the high score?
Your ship isn't the only one lost in the asteroids, it seems. Once in a while a satellite will fly by, firing shots randomly through space. Be sure to keep your ship clear of those shots. You can also shoot back, and you'll earn points for every satellite you destroy. Then, later in the game, smaller UFOs begin to appear. UFOs don't just fire randomly; they have their sites set on your ship! Use your thrusters to keep plenty of distance between you and these UFOs, and also keep your finger on the trigger. UFOs are worth plenty if you can destroy them first!
If you find your ship trapped, you still have hope. Hit the hyperspace button to warp your ship out of danger. Be sure to use hyperspace only as a last resort, however. Your ship just might warp back into even worse danger!
Each game of Asteroids continues until all your ships have been destroyed. Good luck!