Complex sentence: A tentative release date was set for the end of 2007, however, at the 2007 Tokyo Game Show, the date was pushed back, but was mentioned to be nearly ready for future release in Japanese arcades.
Split into simpler sentences: A tentative release date was set for the end of 2007. However, at the 2007 Tokyo Game Show, the date was pushed back, but was mentioned to be nearly ready for future release in Japanese arcades.