Development and release
Astro Boy: Omega Factor was co-developed for the GBA by Treasure and Hitmaker produced as part of a collaboration between game publisher Sega and Tezuka Productions. After a suggestion by Hitmaker president Mie Kumagai, Sega acquired the rights to create games based on the characters of manga artist Osamu Tezuka around the time the 2003 Astro Boy TV series started production to celebrate the in-universe birthday of April 7, 2003 of the titular character.[9][10][11] This would also coincide with the 40th anniversary of the 1963 Astro Boy anime adaptation.[12] Omega Factor was developed in conjunction with Astro Boy on the PlayStation 2 from Sonic Team. After learning that this latter title would have 3D graphics, Kumagai signed on as video game producer of Omega Factor and proposed that it be a 2D side-scroller because its director, Tetsu "Tez" Okano, was very knowledgeable about this style of game and animation.[9] As a long-time fan of Treasure's action games on the Sega Genesis, Okano was eager to involve the studio in the project and replicate the feeling and tone of these earlier releases.[9][10][11]
Okano claimed that the development schedule was tight and that the staff consisted of about ten individuals. He took on the responsibility of overall direction including rough specs, stage structures, and narrative writing while Treasure focused on other aspects.[11] Although its graphics matched the art style of the 2003 series, Okano took some liberties with regards the plot.[13] As a self-proclaimed Tezuka fanatic, the director wished to "balance a different kind of consistency, between the black and white and the color". This meant introducing new story elements while maintaining what he thought late Astro Boy author Osamu Tezuka would have wanted.[9] The inclusion of 47 characters from Tezuka's other manga titles was an homage to the mangaka penchant for having recurring characters throughout his works.[10][11][14] Okano intended the main theme to be Astro Boy cultivating the human side of his heart by meeting these other characters and accumulating impressions.[13]
Omega Factor was chiefly designed and programmed by Mitsuru Yaida, who notably worked on Treasure's run and gun shooter Gunstar Heroes.[10][11][15] Yaida explained that because Omega Factor only had one playable character, they wished to give the player freedom of movement and emphasized the dash mechanic to give the controls more variety.[15] He admitted that he and Okano did not get along in the planning phase of the game. Whereas Yaida wanted to program specifications like points, times, and high scores as development progressed, Yaida wanted them implemented at the start.[16] Yaida said they were added early to satisfy the director but that it was difficult to make them "meaningful" towards the end of production. Due to the GBA's limited RAM and video RAM, he said it was also challenging to program a mechanic which allowed switching between gameplay and menu screens while maintaining event and status displays.[16]
Omega Factor was released in Japan on December 18, 2003.[17] Sega waited until the overseas premiere of the new TV series before releasing the game outside Japan.[18][19] During this six-month wait, the developers took the opportunity to rework some aspects for the localized version. Some level layouts were filled with more enemies, certain enemies were given different attacks, frame rate slowdown was improved, and a new third difficulty setting was added. Sega released Omega Factor in North America on August 17, 2004 while THQ published it in Europe on February 18, 2005.[20][21][22]
