High Quality Content by WIKIPEDIA articles! Wonder Boy in Monster World, known in Japan as Wonder Boy V: Monster World III, is a side-scrolling action RPG originally developed by Westone Bit Entertainment and published by Sega for the Mega Drive/Genesis in 1991. It is the fifth game in the Wonder Boy series and the third game in the Monster World sub-series, following Wonder Boy in Monster Land (Super Wonder Boy: Monster World on the Japanese Sega Mark III) and Wonder Boy III: The Dragon`s Trap (Monster World II: Dragon no Wana on the Japanese Game Gear). It was also the last Wonder Boy game that was given an official English release.