Use the left/right arrow keys to move your spaceship. Use the space bar to shoot at the enemy space fleet and at the flying saucers. Avoid enemy bombs which will take one of your lives when they hit you. The game ends when you run out of lives or if an enemy ship reaches the bottom. If you destroy all enemy ships, then you advance to the next level and gain an extra life. You also gain an extra life each time you shoot a flying saucer.
