Use the WASD or arrow keys to move left, right, up, and down. Click on the screen or press the SPACE BAR button to shoot the obstacles such as laser walls and enemy turrets. With each wall you pass through, you'll earn a point. After destroying some obstacles, an enemy vehicle will arrive to check things out. It'll try to shoot you down, so dodge the fire as much as you can. You can collect power-ups to gain an advantage.