Originally, the
Mega Man X3 team had no plans to provide a sequel until their superiors from Capcom aimed to try the
X series on new hardware. The team aimed to make Zero different from X, he was remade as a proper samurai-like warrior who wields a Z-Saber instead of shooting like X. In order to get the approval to make Zero playable, the developers gave him special moves based on the
Street Fighter fighting game series to compensate for lacking X's powers. In particular, Capcom struggled in the beginning with the number of backgrounds they had to draw, but were pleased with results. There were twice as many sprite animation patterns to create. Since there was too much data creating the player characters, they had to employ a compression routine to store it all, and divide the stages into two sections. Designing X's armors proved difficult since the character looks different depending on which parts the player obtains first. Instead of designing the game's various pieces of artwork as he had done in the past,
Keiji Inafune focused his attention on being a
producer. He was also involved in creating the game's storyline, a role he described as "only slightly less than it was for
X1". In regards to Zero, Suetsugu noted that while he looked appealing, his drawings overshadowed X. Meanwhile, he lamented how brutal was the story of the heroine Iris. Suetsugu spent four days coming up with the initial blueprint. After tinkering with the
Mega Man X3 armor parts, he noticed that attaching them in specific ways made it look like an airplane. He recounted creating the armor as an extremely difficult yet fun task. Zero was intended to have his own Ultimate Armor, but the development team chose to not finalize it. The game's musical score was composed by Toshihiko Horiyama. The score features the opening theme and the closing theme "One More Chance", both sung by
Yukie Nakama. All of the game's instrumental and vocal music was compiled on the
Capcom Music Generation: Rockman X1 ~ X6 soundtrack released by Suleputer in 2003. The theme songs were also included on the
Rockman Theme Song Collection, published by
Suleputer in 2002. but it was delayed and made
multi-platform. Both console versions of
Mega Man X4 were released in Japan on August 1, 1997. The cover art for the Japanese Saturn version depicts Zero standing alone in a dark setting. Inafune stated this idea was weird, there was a still a group of hardcore fans wanting this. The American localization of the
Mega Man X4 PlayStation version was originally put on hold after
Sony Computer Entertainment America denied Capcom permission to release it in the United States, reportedly due to their policy against 2D games. However, after persistent talks with the company, Capcom finally convinced Sony to allow the game a release. According to a Capcom spokesperson, the reasoning behind the delay was that
Mega Man X4 "had just gotten lost in Sony's back log of games waiting for approval". The PlayStation version was released on August 1, 1997 in North America, while the Saturn version came out in the early part of the following week. Customers who preordered either version of the game through Capcom's online store were given a
Mega Man X4-themed T-shirt. Capcom's designated European distributor,
Virgin Interactive Entertainment, opted not to release the Saturn version in Europe, though the PlayStation port was released in that region on October 13, 1997. It was later ported to the Windows in 1998 in Japan. A Japan-exclusive Windows reissue by MediaKite Distribution in 1999. A mobile port focused on X was released on December 1, 2011, while the Zero version on January 5, 2012. ==Reception and legacy==