Defend Earth against insect invaders! The gameplay is a mix between Galaxian and Defender. The alien bugs will attack you and swoop down and steal the uranium drums at the bottom of the screen. As they fly away with the drum, you have to shoot them before they reach the top of the screen to retrieve it. During the game, the space station on the left will load in all uranium drums and then make a connection to the satellite dish on the right, thus ending the level. At the end of each level you get 200 bonus points for each refueled uranium drum and -200 points penalty for each stolen drum. Occasionally a UFO will fly from left to right at the top of the screen. The blue box will display bonus points or the word "combat", indicating what you'll get if you shoot the UFO. Combat means you'll play a combat round where you have to shoot a horizontally moving alien as many times as possible. With each hit, you'll get 350 points and the alien will change direction and gain speed.