"Enemy Zero" began life on Sony's PlayStation. Its unveiling at the 1996 PlayStation Expo in Tokyo was described by journalists as the highlight of the show. Irritated by Sony's failure to meet even a third of preorders for the PlayStation version of "D" (and to a lesser extent, their policy that all marketing for third party games had to be approved by them), at a press conference during the expo Kenji Eno made a shocking move. Eno showed a preview of "Enemy Zero". At the end of the clip the PlayStation logo appeared, but slowly transitioned into the Sega Saturn logo, indicating that the game would now be a Saturn exclusive. Despite popular opinion that the Saturn cannot handle 3D games as well as the PlayStation, Eno commented "...the PlayStation and the Saturn aren't that different, so moving it Zero to Saturn wasn't too difficult." The game was written by Yūji Sakamoto, who later went on to written Crying Out Love in the Center of the World and Quartet. Fumito Ueda, director of the cult video games "Ico" and "Shadow of the Colossus", worked as an animator on this game, before becoming a video game director. "Enemy Zero" was in development for nine months.