Mega Man Zero 4 [a] is a video game developed by Inti Creates and Natsume and published in 2005 by Capcom for the Game Boy Advance (GBA) handheld. It is the fourth and final installment of the Mega Man Zero subseries of the Mega Man franchise and is set several months after the events of Mega Man Zero 3 . The European version featured a completely different logo, which was also used on Mega Man X7 , Mega Man X8 , Mega Man X: Command Mission , Mega Man Zero 2 , Mega Man Zero 3 , Mega Man Network Transmission , Mega Man Battle Chip Challenge , Mega Man Battle Network 3 , Mega Man Battle Network 4 , and Mega Man Battle Network 5 . The game deals with Dr. Weil's reign over Neo Arcadia in which humans, who have been reduced to second-rate citizens, begin to escape in large numbers to the last-known livable location on the planet, Area Zero, beginning a conflict between the two groups. The effects of this war eventually drive Zero and the Resistance to protect Area Zero and its inhabitants from Dr. Weil.[4]

Since its original release, it has been brought to the Nintendo DS family of systems as part of the Mega Man Zero Collection in 2010 and the Wii U's Virtual Console in 2016. In February 2020, it was released on PC (Steam), Nintendo Switch, PlayStation 4, and Xbox One as part of the Mega Man Zero/ZX Legacy Collection .

Several months after the destruction of Omega, Dr. Weil has assumed a dictatorial reign over Neo Arcadia, forcing many humans to flee. In response, Dr. Weil labels the escapees as Mavericks and begins to purge them as if they were Reploids.

A fleeing caravan led by a human journalist, Neige, is attacked by Dr. Weil's army. Zero, Ciel and a small band of Resistance fighters happen upon them and come to their aid. Neige explains they were en route to Area Zero, the crash site of the space colony Eurasia and one of the last natural habitats on Earth that can support human life.[5] Shortly after parting ways, Zero learns of a plot called "Operation Ragnarok", meant to destroy all environments outside of Neo Arcadia in order to force humans to return and live under Dr. Weil's rule.[6] Helping Dr. Weil on his quest are a group of violent Reploids called the Eight Einherjar Warriors. They are led by a military Reploid named Craft, who has a romantic history with Neige, thus creating conflicting thoughts within him.

After defeating four of the Einherjar Warriors, Area Zero comes under attack by Neo Arcadia. Zero defends it and is forced to battle Craft. Neige breaks up the fight, but she is kidnapped by Craft, who escapes. Zero chases him to a prison where Neige is held and eventually rescues her.

Later, Zero eliminates the remaining Einherjar Warriors, but Ciel intercepts a radio message from Dr. Weil. He announces he is going to use Ragnarok, an orbiting satellite weapon, to wipe out Area Zero.[7] Before Dr. Weil can use it, Craft turns on him and fires Ragnarok at Neo Arcadia in an attempt to kill Dr. Weil, which leaves the city in ruins. Zero, deeming Craft to be too dangerous, defeats him, and Craft succumbs to his wounds.[8][9]

Ragnarok moves on a crash course for Area Zero, and Zero makes his way there to find that Dr. Weil somehow survived the destruction of Neo Arcadia. Dr. Weil reveals that while he is human, he was made into a bionic-reploid hybrid by the people who exiled Omega and himself into space at the end of the Elf Wars. His new body is incapable of aging or dying, as it constantly repairs itself.[10] Believing he can survive the impact of the crash and personally oversee the destruction of Area Zero, Dr. Weil fuses himself with the Ragnarok core and attacks Zero. After an intense battle and the destruction of Dr. Weil's body, Ragnarok breaks apart, but leaves Zero no means of escape.

Ciel runs through Area Zero where she learns that Zero did not teleport back.[11] Heartbroken and distraught, Ciel runs off and ends up on top of a hill, where she breaks down in tears while pieces of Ragnarok burn through the atmosphere. Afterwards, she stands up and expresses her faith in Zero, hoping that he'll return someday while promising to carry on his mission of maintaining peace between humans and Reploids. The final scene shows Zero's shattered helmet somewhere in the desert.

Starsgame has programmed and prepared this game for smartphones (Android operating system).