Well I can't say you are the first to make a megaman style game but Maybe you can make some changes. First how are the defining aspects of lask going to be layed out? (i.e. levle format, type of weapons, enemies, ect)

you should write down (or type) a basic description of what you want your game to be. Heck you have already started. While you most likely will not follow this plan to the T it will help both you and those of us who give you feedback later on.

Yet again I wish you luck.