In Mega Man 6, the whole world is alive and buzzing with word of the 1st Annual Robot Design Contest. Hundreds of robot designers from all corners of the globe enter their most powerful robots into the contest in hopes of taking home the ultimate prize. The sponsor of the contest, the mysterious Mr. X, suddenly declares that he has decided on winners...and takes 8 of the Robot Masters for his own purpose...taking over the world!! Mega Man confronts him and demands an explanation, and what Mr. X replies with shocks him. Mr. X declares to Mega Man that he had been using Dr. Wily as a puppet the entire time, and now he would take over the world, and nothing could stand in his way! Mega Man finally decides to stop Mr. X once and for all, and sets off to defeat his 8 new Robot Masters and then the madman himself!
Mega Man 6 is the only game in the series to be exclusively licensed to Nintendo.
Like Rockman 5 before it, Rockman 6 also has a manga adaptation, and like the manga for Rockman 5, it follows along with the story of the game but ups the ante by having Rockman actually talk and interact with the Wily Robots! Also like the Rockman 5 manga, you can find the Rockman 6 manga under the BomBom manga label, and it seems to also have been penned by the same guy who penned the Rockman 5 manga.
This is the only NES Mega Man game not released in Europe.
Robot design contest
For the most part, most of the Wily Robots/Robot Masters from Rockman 2 onward were designed by entries to Robot Design Contests held by Capcom. However, Rockman 6 had one that was a little different. Capcom used to stick only to Japan for entries for these contests. When Rockman 6 was being designed, Nintendo of America decided to hold a design contest of their own, open to North America. Two American entries (Knight Man and Wind Man) were selected and used in the final game. All the rest are from Japanese designers.