Mega Man 4 was published by Capcom for the Nintendo Famicom in 1991.
Other than a new intro sequence (still not making much sense having been badly translated into English), a new set of bad guys, and some newly-designed levels, there’s not a great deal different in this game to what has preceded it.
Actually; I lied. That’s not entirely true – there are mid-level boss fights in this game – which I think were new to the series in 1991. I could be wrong. Anyway… What have the Romans ever given us?!
Mega Man 4 does feel more difficult than the previous games, and the levels also feel shorter… so I’m not quite sure what to make of it. All the mechanics and jump timings are the same as before, which I guess is most important.
In this fourth game the protagonists are: Ring Man, Dive Man, Skull Man, Pharaoh Man, Bright Man, Toad Man, Drill Man, and Dust Man. And – of course – you fight Dr. Wily at the end of the game – as usual – because he’s the main troublemaker.
Mega Man‘s dog, Rush, also makes another appearance in this, having debuted in Mega Man 3.
More: Mega Man 4 on Wikipedia