In Space Ace you play the heroic Ace who must stop the evil Commander Borf from taking over the Earth! Borf plans to reduce all of humankind to infants and take over the planet. Only two people have the courage and strength to stop Borf and save Earth: the beautiful Kimberly and the heroic Ace. But as they approach Borf's stronghold, Ace is hit by the Infanto Ray, changing him into a child, and Kimberly is kidnapped by the evil madman! The fate of Earth is in your hands!