You are in deep space, test-piloting the latest in space technology, when your home planet Libnah learns of a surprise attack of the diabolical, war hungry DEMENS from the NATIS galaxy. A radiation death-ray threatens to wipe out your entire race. It's up to you to conquer the enemy solar systems!
As the dreaded DEMENS death-ray gets closer and closer, your computer has classified their solar systems from lightly defensed to almost invincible! It will guide you through harder and harder systems until you have conquered their entire civilization.
The object of the game is to score the most points by destroying enemy defenses, defeating their planets, and conquering their solar systems.
You have defeated a planet once you destroy all its weapons. When you have conquered all the planets in a solar system, you advance to the next. Whenever a player is hit, he loses a ship and he gives up his turn to the next player. If a planet is defeated and the player dies, he still moves on to the next planet.
The more gravity a planet has, the more difficult it is to control your spaceship. The larger the planet, the stronger the planet's gravity. The higher a planet's solar system, the better its defenses. As you fly closer to the planet, the effect of its gravity increases.
The alien defenses have 3 types of weapons:
1. Kamikaze combat ships
2. Ground-to-air missiles
3. Super fighting (killer) satellites
Planets also have dangerous asteroids floating around them.
Learning to control your spaceship against the ever changing forces of gravity is the most difficult aspect of the game. There is also a SLIPPER built into the ion drives of the ship, which enables you SLIP in one direction and face another without accelerating in the direction of the ship; e.g. accelerate up, then face right for an instant and let go of the joystick. The ship will continue to slide up while the player faces right and strikes a target. Becoming skillful at the SLIPPER will prove a powerful advantage over the enemy.