Castaway: The Ordeal Begins

Castaway: The Ordeal Begins is a game by John T. Gallon that features the player landing on a foreign planet, and must proceed to shoot his way through the game. The back story describes the results of the Slrrian War, and how the Terran Stellar Union had failed to defend its lush terraformed planets, and the practice of cloning human prisoners to conquer more Terran worlds unbreathable to them and make up for their low birthrate (probably to accommodate the default human sprites).