The game's protagonist is Bonk, a strong caveboy who battles dinosaurs. Bonk can use pieces of meat as power-ups, these lend him special abilities and make him stronger. There are three stages of powerup: his normal self, a second stage during which he can stun enemies by pounding on the ground, and third stage where he becomes temporarily invulnerable. In the original game, the second stage turns Bonk into a caveman, but in Japanese versions of the second and third game, he becomes a cavewoman. This gender transformation was scrapped for the US entries in the series.