For much of MM4, it looks as though Dr. Wily has finally gotten the message - your antagonist is identified as Dr. Cossack (a bad Russian stereotype, in case it's not obvious). However, by the time you finally get to Dr. C, it's revealed that Wily was the one pulling the strings all along - and so, with a sigh of 'Here we go again,' you plunge into yet another Skull Castle en route to yet another showdown with Wily. This was probably the first game that showed signs of wear-and-tear in the Mega Man series; the whole premise was getting rather shopworn and predictible, yet the Blue Bomber *himself* remained as popular as ever, so Capcom kept churning 'em out. MM4 featured the first appearence of the Mega Buster - the charged-up version of Mega's default pea shooter - as well as Flip-Top.