From what I understand, you can use a controller to play this game.
As for difficulty. When I did my first blind run I found some stages a little difficult, but no more than any other MM game's stages. The real difficulty comes from the bosses. Unlike regular robot masters, they all have at least 3-4 techniques that they use quite randomly(some less random than others).
After a couple playthroughs though, it gets really easy, imo. So much so that I can beat the entire game(including both secret bosses) in less than an hour.
Feel free to apply sarcasm tags if you didn't like my post.
The level where you have to beat all 8 bosses in a row on only 3 lives is a little rough because the bosses don't have a set pattern, so it's not as easy to just memorize what they do and blow through them all. Vega's level and the boss himself were pretty annoying until I got used to them. Besides that though it's actually easier than the regular mega man series. And yes it supports a controller.
"Siegfried: He has no need for words, he speaks with whiffs." - Wandrian Official General of the Fire Emblem: Awakening Boards