Mega Man 4

Mega Man 4 is a 1991 Capcom action game for the Famicom and introduces the series' most significant gameplay evolution: the Mega Buster charged shot, allowing players to hold the fire button and unleash a powerful energy blast. The apparent villain is Russian scientist Dr. Cossack, though Dr. Wily is once again pulling strings from the shadows. Players must defeat eight Robot Masters — including Drill Man, Pharaoh Man, and Skull Man — claiming their weapons before storming Dr. Wily's fortress and uncovering the truth behind the conspiracy.