I was so looking forward to playing this, however no rom I have seems to work for this game in drmdx. Some dont go further than the Loading Rom... message, while others make it as far as the title screen then crash on pressing start...
Same here. Monster world doesn't work , but monster lair does (as far as i can remember, as i'm currently at work, but i know that there is one working while the other not)
Try playing Wonderboy in Monster World 5 (aka Wonder Boy 6), it is very similar and a nice game, too. It works flawlessly so far and it'll keep you busy for a while.
Be sure to get the translated version, though, unless you understand japanese. ;-)