Dragon Ball Z Gaiden: Saiyajin Zetsumetsu Keikaku

The game follows Dr. Lychee, a survivor of the Tuffle race annihilated by the Saiyans. Lychee manages to escape from the planet with a ship containing Hatchhyackku, a super computer able to create "Ghost images" of other warriors, though he is killed soon after. Hatchhyackku creates a ghost image of him to get revenge on the surviving Saiyans. He places machines that emit a gas capable of destroying life on Earth, so Goku, Gohan, Vegeta, Future Trunks, and Piccolo rush to destroy the devices located around the planet.