When a game is successful (or movie, TV show or style of music, for that matter), you're undoubtedly going to see a billion clones trying to cash in on the original game's success. Such was the case with the Vic Tokai NES game The Krion Conquest. It was almost bit for bit a copy of Mega Man - right down to the way the main character Francesca looked, moved, jumped, and accessed special weapons and other abilities. You couldn't select levels or gain powers from bosses like you could in the Mega Man games (instead, you start with all of your powers already available), but other than that, The Krion Conquest could have been the lost game in the Mega Man series.
That's not to say that The Krion Conquest was a terrible game... it was a lot tougher than most of the Mega Man games, it had a great anime-style opening cinema, and was fun to play. If you're a Mega Man fan at all, you may be interested in checking the game out. It's a Mega Man game at heart, but it's different enough to warrant a look.
For a more in-depth look at the similarities between The Krion Conquest and the Mega Man games, check out this article Flying Omelette has posted in the NES Rip-Offs section of her site, Flying Omelette's Kitchen.