Thousands of asteroids are on a collision course with Earth, and we've activated the Global Defense System to stop them. And you're in charge -- but don't worry... we'll pay you for your trouble. Use the Global Defense System asteroid-killer platforms to blast the asteroids before they wipe out humanity. You don't always have to destroy the asteroids. Just deflect them enough to keep them from hitting the planet. After each level, you have the chance to upgrade your platform with more powerful weapons. Try to beat my high score of 815,350!.