The player controls a small insect-like Bug Blaster. It is moved around the bottom area of the screen with a trackball and fires small darts at a segmented centipede advancing from the top of the screen through a field of mushrooms. Each segment of the centipede becomes a mushroom when shot; shooting one of the middle segments splits the centipede into two pieces at that point. Each piece then continues independently on its way down the screen, with the rear piece sprouting its own head. If the centipede head is destroyed, the segment behind it becomes the next head. Shooting the head is worth 100 points while the other segments are 10. The centipede starts at the top of the screen, traveling either left or right. When it touches a mushroom or reaches the edge of the screen, it descends one level and reverses direction. The player can destroy mushrooms (a point each) by shooting them, but each takes four shots to destroy. At higher levels, the screen can become increasingly crowded with mushrooms due to player/enemy actions, causing the centipede to descend more rapidly.