Mega Man 4 is the fourth game in the series, developed by Capcom for the NES. You control Mega Man, fighting a new set of Robot Masters and the mysterious Dr. Cossack, who is framed by Dr. Wily. The gameplay introduces the "charge shot," which allows Mega Man to hold the fire button to release a powerful energy blast, a significant addition to the combat system. The game also features the "Rush" system with new transformations like Rush Bike and Rush Jet. The Robot Masters include iconic characters like Pharaoh Man, Dive Man, and Dust Man. The levels are more complex, with new environmental challenges. A trivia: Mega Man 4 was released during the peak of the series' popularity and was the first to feature the charge shot as a standard ability. The graphics are more detailed, with enhanced backgrounds and smoother animations. The music is fast-paced and catchy, composed by the Capcom sound team. Critics praised the charge shot, the level design, and the overall quality. It supports one player. The final boss is Dr. Wily, who returns as the true antagonist. Mega Man 4 is a solid entry that continues the series' high standard.