Mega Man 4 had a subtitle in Japan as “A New Threat.”
While the charge shot on Mega Man’s megabuster seems simple today, it didn’t come out until Mega Man 4.
Mega Man’s creator Keiji Inafune considers Mega Man 3 as the least polish game in the classic series. He wanted more time to work on the game but Capcom insisted they publish it on their timetable.
Mega Man’s robotic dog Rush was actually meant to be a bird but they changed it before they completed Mega Man 3. In Mega Man 5 they actually bring back this idea with Mega Man’s bird friend Beat.
Before Mega Man 3 was published, the team at Capcom almost gave him long hair but eventually opted for a helmet.