Tri-Crescendo, the Japanese developer behind Eternal Sonata, wanted to make the game an Xbox 360 title from the get-go. While the studio had previously worked on GameCube title Baten Kaitos, the Wii was not the platform of choice. According to game site Siliconera, the controller and the graphics made bringing Eternal Sonata to the Xbox 360 a no-brainer. What about a PS3 version? Publisher Bandai Namco told Siliconera that it was "not aware" of a PS3 version at the moment. How could it not be aware of that? It's friggin' Bandai Namco! The Japanese box for Eternal Sonata (AKA Trusty Bell) doesn't have an "ONLY ON XBOX 360" stamp on it. Thus, the game should be treated as such.
Eternal Localizer Talks [Siliconera]