Wonder Boy III - Monster Lair (set 6, World, System 16B) (8751 317-0098)

Wonder Boy III - Monster Lair is a cooperative platform and scrolling shooter released by Sega / Westone in 1988. Players control one of two characters as they navigate through a series of interconnected underground areas filled with enemies and obstacles. Gameplay involves running, jumping, and firing projectiles to defeat monsters and progress deeper into the lair. This version, identified as set 6 on the System 16B hardware, is an export release developed in Japan. The game’s technical identification number is 317-0098. It builds upon previous entries in the Wonder Boy series but features a distinct shift in gameplay style blending platforming challenges with shooting mechanics. A version of this title was later released for the Sega Mega Drive console in Europe.