In the Blue Bomber's 22 year history, there's been quite a few games that haven't received an official English localization and remain, to this day, exclusive to Japan. One such title is 1993's Wily and Right's RockBoard, an obscure Monopoly-like game for the Famicom. Supposedly, Nintendo believed the game promoted gambling and, as such, chose not to release the game in the States... or anywhere else, for that matter.
17 years later, RockBoard has yet to see an official English translation (although a fan translation exists). However, a recently uncovered magazine article suggests that at one time, Capcom was in the process of localizing the game in English under the name of 'Mega Board':
Lost Levels forum member ReyVGM stumbled upon this blurb in an old Spanish gaming magazine article previewing a variety of then up-and-coming Capcom games shown off at the 1993 Consumer Electronics Show. 'Mega Board' is one of the games featured, and as you can see, the screenshot for the game features English text. The text refers to the numerous options players can take when traversing the board, like "ROULETTE", "MEANS" and presumably "NEGOTIATE."
Needless to say, this is a truly fascinating discovery. It begs the question of just how far along the English version was in development before it got canned, and if it still exists in some form.
Well, here's hoping we'll be learning more about this in the future!