Rockman is hungry for mushrooms, and must grab them from the treacherous prehistoric screens of this action game. To get to many of them, he will have to push boulders out of the way. He can't jump, but the levels each contain some long red vertical beams which allow the player to move up and down within them. Enemies move on a pseudo-random pattern and must be avoided. There are also skulls to avoid contact with, as this will cost him a life - as will going too long without eating a mushroom. Passwords allow the player to return to a later level.