constraints. The camera was switched to the right analog stick of the DualShock controller instead of the shoulder buttons and the Gummi Ship travel was reworked. The combat system was completely redone and did not use any animations from the first game. Because Sora had matured, Nomura wanted his fighting style to reflect that. Other changes included more integration between exploration and battles. The variations in combat styles associated with each Drive Form and the introduction of the Reaction Command were added to give players more choices in battles. The inclusion of worlds based on live-action Disney films was aided by technology that generated the character models from live-action pictures. Audio Musical score Like the first game, Kingdom Hearts II features music by Yoko Shimomura and Hikaru Utada. The Original Soundtrack for Kingdom Hearts II was composed by Shimomura and released on January 25, 2006. The opening orchestration and ending credits theme were arranged and orchestrated by Kaoru Wada and performed by the Tokyo Philharmonic Orchestra. The main vocal theme for the original Japanese release was "Passion", written and performed by Utada. The English version of "Passion", "Sanctuary", was used in the Western releases. Utada's involvement was announced on July 29, 2005. According to Nomura, the vocal theme ties in even more closely with the game's story than "Hikari" ("Simple and Clean") did with Kingdom Hearts and Kingdom Hearts: Chain of Memories. The CD single for "Passion" was released on December 14, 2005 and "Sanctuary" was first previewed on MTV's official website in early 2006. Voice cast Kingdom Hearts II features well-known voice actors for both the Japanese and English versions. Many of the original voice actors from the first Kingdom Hearts reprised their roles; Miyu Irino and Haley Joel Osment as Sora, Mamoru Miyano and David Gallagher as Riku, and Risa Uchida and Hayden Panettiere as Kairi. New voice actors included Kōki Uchiyama and Jesse McCartney as Roxas, Iku Nakahara and Brittany Snow as Naminé, and Genzō Wakayama and Christopher Lee as DiZ. A special effort was made to preserve the official voice actors from the Disney movies used in Kingdom Hearts II. Many actors reprised their Disney roles for the game, including Ming-Na Wen as Mulan, James Woods as Hades, Bruce Boxleitner as Tron, Chris Sarandon as Jack Skellington and Zach Braff as Chicken Little. Some voice actors from the related television series or direct-to-video sequels were chosen