As J.J., an operative of the White Knights, players must Infiltrate the Norsa Empire's underground base and steal their plans for domination. Zillion features side-scrolling action with an emphasis on disabling traps and navigating the labyrinth-like base. While exploring the base J.J. will need to locate five floppy disks, as well as rescue his friends Apple and Champ. Following their rescue, both characters become playable and can be switched to at any time. Apple is weaker than J.J. but can jump higher and Champ is the strongest character but also the slowest.