Uma gigantesca explosão espacial envia dois meteoros estranhos que colidem com a Terra. A chamada sai e Mega Man acelera para o local. Lá ele vê seu arqui-rival, o Dr. Wiley, fugindo da cena, agarrado a um dos misteriosos meteoros metálicos. Agora Mega Man deve descobrir o segredo do segundo meteoro em uma corrida para ficar um passo à frente do Dr. Wiley e sua nova raça mortal de robôs superpoderosos. • Batalhe em 14 estágios enormes para enfrentar oito novos inimigos desonestos. • Múltiplas atualizações para Mega Man - personalize de acordo com suas especificações a cada jogo. • Intensas introduções de anime japonês, cenas cortadas e telas de cinema. • Animação incrivelmente fluida e fundos altamente detalhados.

Taking place in the 21st century (the ambiguous year 20XX) and after the events of Mega Man 7, two alien robots engage in a battle in the depths of space. Ultimately, both of them plummet towards Earth, critically injured. On Earth, humanoid robot Mega Man and his robot canine companion Rush are caught in a skirmish with his rival Bass, who still wants to prove himself to be stronger than Mega Man. Thanks to the timely intervention of his sister Roll, who was bringing a message from his creator Dr. Light, Mega Man manages to subdue Bass long enough to leave. Bass swears that he will get back at Mega Man for his "cowardice". Dr. Light asks Mega Man to investigate strange energy readings on a nearby island. [5] On the island, Mega Man finds Dr. Wily flying away with a strange purple orb. Before chasing him, he sees a damaged robot and asks for Dr. Light to pick it up and try to repair it. Dr. Wily then releases four new advanced and modern Robot Masters to combat Mega Man: Frost Man, Tengu Man, Clown Man, and Grenade Man. Each time he destroys one, he receives a purple orb like the one Dr. Wily captured. Each of the Robot Masters are empowered with a strange energy, and it seems that this power comes from the new energy cores that Wily has infused them with. After Mega Man defeats the four Robot Masters, he returns to the lab and brings Dr. Light the energy cores he retrieved; Dr. Light examines them and realizes that they are a powerful form of energy, which Dr. Wily must not have in his possession. After they leave the lab, the robot awakens and sees the energy cores, becoming enraged and flies off into the distance. Mega Man follows him to a mine shaft on the other side of the globe. After battling the robot, Proto Man shows up and tells Mega Man that Dr. Wily's new fortress, "Wily Tower," is just ahead. Mega Man goes there but is captured by one of Wily's giant robotic creations. The robot saves him and introduces himself as Duo. Duo explains to Mega Man that the purple orbs are "Evil Energy" and he has been traveling the universe, tracking down this energy and trying to destroy it before it engulfs the entire world. However, Wily Tower has a barrier around it that prevents him from taking out the source. Duo tells Mega Man to destroy the four other Robot Masters that hold the key to the barrier (Astro Man, Sword Man, Search Man, and Aqua Man), while he collects and extinguishes the rest of the world's Evil Energy. Once the remaining Robot Masters are defeated, Wily Tower's barrier is lifted and Mega Man makes his way through it, defeating the hordes of robotic henchmen inside, including Bass, who uses a piece of the Evil Energy to amplify his powers, and ultimately, the evil doctor himself. The "Evil Energy" is destroyed before it is allowed to spread throughout the world, but it manages to infect Mega Man before being destroyed, and Wily's newest compound is demolished with Mega Man inside, who is dying from the Evil Energy. Duo arrives, and seeing the goodness and justice in his heart, cures him of the evil energy, eradicating the last remnants of the Evil Energy on Earth. Proto Man catches up to him; Duo then says that his mission is done, and leaves, but not before asking Proto Man for a favor. Mega Man then wakes up in Dr. Light's Lab and is reunited with Light, Roll and the others who tell him that Duo saved him. He then walks outside and finds Proto Man, who gives him a message from Duo: "Thank You. "