FFXIII producer Yoshinori Kitase has admitted that work on the 360 version of the game didn't start until after the PS3 playable demo was released - in April.
"Up to the trial demo version that was released [in April] in Japan, [FFXIII] was PS3-only in terms of development," Kitase said.
"The Xbox 360 version is definitely following after the PS3 version, but [we] were finally able to come to a point in the PS3 development where some of the staff could take their hands off and start programming the 360 version," he went on to tell Giant Bomb.