Mega Man 9: Proto Man Mode is a bonus gameplay variant that strips away narrative elements entirely, focusing instead on pure mechanical challenge. Players control Proto Man, Mega Man's mysterious rival, through the same eight Robot Master stages found in the base game, but with adjusted difficulty and unique mechanics tailored to this character. Without an overarching plot to frame the action, the mode prioritizes combat and platforming skill, letting players experience familiar levels through a fresh lens with a different protagonist.