In Terra7, the planet is under attack, and the only way to stop the enemy is to activate a laser-equipped satellite. This satellite activates only when it reaches a specific point on the screen and after 10 batteries are fully charged. Batteries are charged by technicians who stay on Terra7 when enemies are destroyed—one battery per 25 kills, requiring a total of 250 enemy eliminations. You control a robot with a maximum of 5 shields, losing one if hit by a missile, enemy, asteroid, SmartBomb (S), or by failing to rescue or accidentally killing a lost astronaut. Shields can be regained by colliding with an Energy Module (E), but not by shooting it. SmartBombs destroy all on-screen enemies and add 3 kills to your counter. The game ends whether the mission succeeds or fails.