Development of the Xbox 360 version of Final Fantasy XIII began only two months ago, after the release of the PS3 demo of the game, Square's Yoshinori Kitase said.
Worries that the Xbox 360 version of Final Fantasy XIII would never see the light of day until somewhere in the horribly vague expanse of time known as "next year" (oh it's so far away!) were quelled at E3 when Square-Enix showed up to not only demo FFXIII on 360, but announce a Spring 2010 release window for both versions of the game.
The game looked sharp running on the 360, essentially identical to all of the PS3 footage that we've seen thus far. It's a bit surprising to learn, then, that the FFXIII team has only been working on the 360 version of the game for a couple months, and with limited resources.
"Up to the trial demo version that was released [in April] in Japan, [FFXIII] was PS3-only in terms of development," producer Yoshinori Kitase told GiantBomb. "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."
I had been under the impression that work had been going on for both versions at the same time, but this apparently isn't the case. Kitase had said that "it's like we are going to keep on the go simultaneously," which I suppose now means that PS3 development has gotten far enough where the team can work on polish while work on the 360 version gets going in earnest.
Considering how nice the game looked at E3, we can assume that Square's Crystal Tools engine, built for multiplatform development, is genuinely doing its job, and the two versions may be more or less identical. Aside from the lack of Japanese voice-tracks on the 360 version, which could be a deal breaker for the genuine Nihongoloids out there. Including myself - when it comes down to Achievements versus the original Japanese language track, I have to say I'm personally inclined toward the latter.