Your mission is to find and destroy and army of mutant bugs who have made their homes in caverns deep beneath the planet's surface. A labyrinth of dangerous tunnels leads down to these caverns which you must negotiate skillfully in your spaceship. Once you've destroyed the bugs in a cavern, you must return through the tunnels to the planet's surface. But beware!! The surface is not safe, it is covered with a network of randomly pulling endergy fields that can easily destroy your spaceship.