Alex Kidd is the brother of King Igul, ruler of Planet Aries. Acting on a rumored sighting of their missing father, Alex travels to the planet Paperock to find him. Why the name? Because the child's sport of Paper-Rock-Scissors is a planet wide institution, and those who visit must display some talent in the game. The only MegaDrive entry in the long-running and popular series of arcade and console games by Sega.
Not very challenging, but not bad for a game made back in 1987.