Developers had been planning a release on the next generation of mobile phones, as those available at the time could not offer all the capabilities they would need. While it was originally claimed to be a mobile exclusive, versions for both mobiles and the PlayStation Portable were being developed, with the latter to be revealed when the former was sufficiently advanced. The original staff members were Tabata, Yusuke Naora and Tetsuya Nomura. Nomura acted as a character designer and creative producer. Between 2006 and 2008, development wavered between inactivity and sluggishness since most of the team was devoted to "". In 2008, it was said to be facing serious problems due to the scale of the project. An issue developers had grappled with was whether or not to make the command buttons used in the game visible on the mobile screen. "Agito XIII" was described as an online RPG using fully rendered 3D graphics similar to console games, as well as having gameplay elements from multiple genres such as MMORPGs, smaller-scale multiplayer-focused games, and standard role-playing games. Other unfinished concepts being developed were a day-night cycle, a calendar system linked to real-world time and dates, and a story influenced by player votes.