Your mission is to fly Killer Watt through tunnels in an underground cavern shooting 12 bulbs to move to the next level. The game is viewed from the side and the screen scrolls left or right when you move your craft. As you search for the bulbs you must avoid or shoot various creatures and depending on the strength of your shield, if you touch one or hit the walls for too long then you lose one of three lives. Once you have shot all 12 bulbs then you move to the far left of the cavern to hit a switch and move to the next level. There are five levels to navigate with each cavern having the same layout, but later ones have more creatures to shoot or avoid. Before you start the game you can select the strength of your shield (1-5) and which level to start on. The joystick or keyboard can be used to control your craft.
The gameplay is action-packed as you try to survive in a hostile underground environment. You must keep moving, shooting and avoiding obstacles while managing your limited lives. With five levels to conquer, the game gets increasingly challenging as the number of enemies and obstacles increases. But with practice and patience, you can overcome the challenges and progress through the levels.