Space War is an action game where two players each control spaceships.
The goal is to destroy your opponent's ship by depleting its energy supply; success will earn you a point. Each ship is capable of flying anywhere on the screen and is also equipped with lasers for attacking your opponent. At the beginning of the game each spaceship has 90 energy units; when no energy is left that ship will be destroyed.
Energy can be depleted in two ways: 2 points are used up every time you fire your lasers, and 5 points are lost if hit by enemy laser fire. Should your energy level drop to 10 points or less, you will be unable to fire your lasers; this prevents you from accidentally obliterating your own spaceship! Energy units can be replenished by flying through one of the two starbases located at opposite ends of the screen.