Mega Man IV

Mega Man IV, known as Rockman World 4 (ロックマンワールド４) in Japan, marks the fourth game in the classic series to be released on the original Game Boy.

Story
Sometime after Mega Man 5, Dr. Wily attends the annual Robot Masters Exposition where he manages to reprogram some of the Robot Masters that were on display. Although Dr. Light and Mega Man were also in attendance, Wily failed to reprogram Mega Man. Thus, Dr. Light sends Mega Man out to stop Wily before he can use his newly reprogrammed robots to wreak havoc across the globe. Mega Man manages to defeat the first four Robot Masters and make his way to Wily's fortress, where he encounters a new Mega Man Killer named Ballade, and although he defeats him, Ballade promptly leaves, opening the way up to where four more Robot Masters lay in waiting. However, after Mega Man defeated them, he made his way to where Ballade was waiting and defeated him for a second time, acquiring the Ballade Cracker, which he used to blast his way out of Wily's crumbling fortress. Mega Man made his way to Wily's new space fortress and defeated Wily, but was trapped in the fortress when Wily activated a self-destruct mechanism. However, Ballade had a sense of self-sacrifice at the last minute and saved Mega Man in the end.

Second Four Robot Masters
Mega Man Killer:
 * Ballade

Other bosses:
 * "Satellite Cannon" (unknown name)
 * "Bridge" (unknown name)
 * Hunter
 * Wily Robo Iron Golem