Released in Japan and Europe for the Mega Drive.
Wonder Boy III: Monster Lair is a quite different game to most of the games in the Wonder Boy series. You play a green-haired dude who must attack the invaders that attempt to collect weapons and use them to destroy the land. The game starts out like a simple platform game, but it's just when Wonder Boy enters the skull further on that the game is transformed into a shoot 'em up, so basically the gameplay consists of action and shooter scenes.