Monster World III/Wonder Boy in Monster World
Seeking to take over Monster World, Biomeka sends an horde of monsters who plague the kingdom of Purapril and controls the Prince of Dark World, who is turned into a monster. The hero Shion sets on a journey to save Monster World, fighting the monsters and saving the Dark Prince, who tells Shion about Biomeka. Shion travels to Biomeka's spaceship and fights him, but ends defeated, so the Dark Prince uses his power to break Biomeka's main cannon, allowing Shion to fight the monster.
At first only a laser will appear from the walls and move around the rails while periodically shooting, but after Biomeka's cover is broken and reveals its eye, two lasers will appear instead of one. The North American version also has a moving floor and a large saw moving back and forth in the floor to make the final boss harder. Despite the defensive mechanisms being on his way, Shion manages to defeated Biomeka. Though Monster World is saved, Biomeka escapes.
Monster World IV
Biomeka (Fear Incarnate in this timeline), called Warera in the remake, hides himself beneath the kingdom of Rapadagna, where he starts feeding on people's dark thoughts. He sends the Four Warlocks, who give Pepelogoos to the inhabitants of Rapadagna, which are actually dark Pepelogoos that drains people of their hopes. The heroine Asha fights the warlocks, but their influence causes Praprill XIII, the queen of Rapadagna, to go mad and turn evil.
The queen attacks Asha, but Pepe, her Pepelogoo, blocks an attack from the queen's dark Pepelogoo and is knocked unconscious. After the warlocks are defeated, Asha fights the Queen again but Pepe, now recovered and fully grown, interrupts the fight and starts singing, making the Queen to recover her senses and all dark Pepelogoos to run away. Asha finds a hole in the castle, which leads to a underground cavern which she follows, finally finding Biomeka in the bottom. Asha fights the monster, who attempts to petrify her, but Pepe appears and blocks Biomeka's gaze, ending petrified himself. Asha finally defeats Biomeka and saves Monster World.
- In The Dynastic Hero, Biomeka is a frog-like creature named Rippen the Beast (サンショウ魔王 Sanchō Maō, roughly "Demon King Sancho" in Japan), and its cannon is a magic object. Instead of the Prince, the four assistant characters appear to help, three damaging the object, and one healing the hero. Its second form resembles Biomeka, being a large one-eyed brain-like creature, but with the addition of "fins", legs, and a tail. It has the same difficulty from the Japanese version of Monster World III.
- In Turma da Mônica na Terra dos Monstros, Biomeka is an unnamed machine controlled by Captain Fray (Capitão Feio). The Prince is replaced by Smudge (Cascão), and its second form shows Captain Fray controlling the machine. It has the same difficulty from the English version of Monster World III.