You are Egbert. Your job is to push the red button on the side of the screen, avoiding the aliens that travel along the sides of the screen. Just touch the red button with your character to push it. There is also an alien egg moving slowly down the center of the screen. You cannot let it reach the bottom, take it to the top or outside the marked center of the screen or it will hatch an alien that will kill you. You can walk to the egg and push your fire button to grab the egg so you can move it up higher to give you time to push the button. In later levels, the buttons slide down the screen. Just keep going to see how high you can get your score.