The fourth of the Rockman Complete Works series contains the most underrated Rockman/Mega Man game of them all: Rockman 4: An Evil New Ambition!!"
In Rockman 4, Dr. Wily is declared as having been killed by the explosion of Gamma. A year passes and Rock, Roll, and Dr. Light are living in peace. But soon, the peace is broken by a new threat.
A supposed colleague of Dr. Light's, the mysterious Dr. Cossack, has sent out eight of his own Robot Masters to find Rockman, whom Cossack blames for the kidnapping of his daughter. Rockman, hoping to clear his name, sets out to find Dr. Cossack, this time armed with a powerful new weapon: the Rock Buster!!
Rockman must now battle with Cossack's fiendish Robot Masters and find Cossack's daughter before it's too late!
The Rockman Complete Works series was only released in Japan.