Wonder Boy III - Monster Lair (JUE) [c] ROM Download can be obtained free for Sega Genesis on EmuGames.net only. Play emulator game in English for the USA region. Wonder Boy III Monster Lair is a Sega ROM that you can download to your computer or play online within your browser. You can also download roms such as PokePark 2 Wonders Beyond and Harvest Moon A Wonderful Life Special Edition that work on all devices including desktop and mobile. Be sure to rate the game if you enjoyed playing this ROM.