Critical Mass is a game set in the future, where you are the commander of a squadron of spaceships.

You will be sent on one of 30 different types of missions, ranging from protecting a convoy, to attacking an enemy starbase, to defending Earth. Combat is carried out using 4 different types of missiles which home-in on the nearest target, so you have to be careful not to destroy your own friends. The game is turn-based, but with missiles homing in on your tail, enemy ships weaving to get out of your line of sight, and sirens screaming warnings at you, it can get pretty frantic.