Mega Man ZX, produced by Keiji Inafune, is the first of two games in the Mega Man ZX series, and features the characters of Vent and Aile. It was released in 2006 and was followed by a sequel, Mega Man ZX Advent.
- Zero - (Flashback)
- Giro - a character very similar in manner and appearance to Zero, Giro is the owner of a shipping company named Giro Express, which specialized in transporting everything, "illegal or not", as well as taking care of children losing their families due to Maverick outbreaks, like Vent/Aile. Unbeknownst to them, Giro is also the owner of Biometal Model Z. He is manipulated by Serpent into fighting Vent/Aile and dies.
- Prairie - is the current leader of the Guardians, having the position since the original leader disappeared. The Guardians take in people on a voluntary basis to defend "Frontier" areas from Mavericks and discover what causes these outbreaks. Although she appears to be in her mid-teens, it is discovered that Prairie witnessed the fall of Ragnarok and the death of Zero a hundred years before, strongly implying that she is in fact Alouette.
- Prometheus - like his sister Pandora, he is a servant of Model W. He wields a beam scythe and uses fire and shadow-based attacks in battle. Albert intentionally created Prometheus and Pandora with short life spans so that they would not be able to betray him.
- Pandora - is a mysterious character who works to revive Model W. She is usually seen with her brother Prometheus. She is very quiet and uses the Ice and Thunder elements.
- Galleon - mass-produced humanoids that are common enemies in the game and its sequel. They are similar to Sniper Joes from the Mega Man Classic games and Pantheons from the first three Mega Man Zero games.
- Powmettaur - the sub boss from Area H, resembling a giant Met.
- Serpent - the head of Slither Inc., Serpent comes into the possession of Biometal Model W, and becomes the antagonist of the game.
- Omega - (cameo)
After the years of constant battle between humans and Reploids, both sides -- seeking peace and equality -- reached an accord. They agreed to pass a law granting humans the same strength as the Reploids' mechanical bodies, and granting Reploids human mortality.
After hundreds of years, humans and Reploids became virtually indistinguishable. The old war seemed like ancient history -- all but forgotten.
Meanwhile, thanks to Slither Inc.'s new machinery for extracting and supplying the world with a fantastic new energy source, the world's serious energy shortages were solved. Slither Inc. were hailed worldwide as heroes!
But, not everyone was fond of Slither Inc....
Somewhere a transporter, eyes filled with sadness, gazes at Slither Inc.'s giant headquarters. This transporter will soon learn what fate has in store...
Mega Man ZX contains elements from the Mega Man X series and the Mega Man Zero series. The players are on a 2-dimensional overlay map with sprites where they engage enemies to finish their mission. When a player receives a Biometal, he is able to change form, gaining various abilities, such as the charge moves, or charging the player's weapon with an element of that Biometal; for example, Biometal H will charge the weapon with electricity. While in a special form, using the form-specific abilities use up weapon energy. When the player receives the other half of the Biometal, he is able to perform a different special ability. This process is called Megamerging.
The player initially begins with only Model X, but upon obtaining Model Z, Model X is used to fuse with the other Biometals. This is called Double Megamerge. At this point, Model X can no longer be used alone for the rest of the game, until after it is unlocked by completing the game with both characters in normal or hard mode. Biometals of the Four Guardians from the Mega Man Zero series are found throughout the game, and these are the only Biometals that can be upgraded with Energy Crystals. These four Biometals use the touch screen in various ways. A seventh Biometal, a special one called Model O, or Model Omega, is available after completing the game and fulfilling certain requirements.