gathered from the opening sequences, most details regarding the story were kept secret until the release. The card-based gameplay of Chain of Memories would later serve to inspire the gameplay of Jupiter's next game, The World Ends with You; originally, the team envisioned a similar card game-based system taking place on the lower screen of the Nintendo DS, but eventually this morphed to a battle system taking place on both screens, with a card game controlled on the upper screen. Audio Much of the music from the original Kingdom Hearts is present in Chain of Memories; the main vocal theme for the Japanese release is , while the English version of "Hikari", "Simple And Clean", is used in the Western releases. Additional and reworked tracks were created for its PlayStation2 rerelease, Kingdom Hearts Re:Chain of Memories. Since the music is reused from the original, a Chain of Memories soundtrack was never released. The new reworked tracks, however, are included on two CDs in the Kingdom Hearts Original Soundtrack Complete. Due to the technological limitations of the Game Boy Advance cartridge size, voice acting was kept to a minimum. Though many characters from Kingdom Hearts were voiced by the cast from before, the Japanese version used the following voice actors: Keiji Fujiwara as Axel; Tatsuya Kando as Vexen, Marluxia, and Lexaeus; and Rieko Katayama as Larxene. A limited amount of voice acting was added only for the battle sequences. Voice clips from the first Kingdom Hearts were inserted into Chain of Memories. The English version is absent of dialogue; voices during Organization battles are replaced with simple grunts, laughter, and other battle cries. Versions and merchandise Like its predecessor, a great deal of merchandise was produced to help market the release of the game. Square Enix released two products to coincide with the release of the video game. The first was a limited edition Kingdom Hearts Game Boy Advance SP set released only in Japan. The set contained the game, a "Kingdom deep silver" GBA SP with the Kingdom Hearts logo, and a carrying strap. The second was a Kingdom Hearts trading card game produced by Tomy. The TCG featured starter decks, playing mats, and booster packs. Fantasy Flight Games later acquired the rights to market it to English-speaking countries. In 2007, a remake for the PlayStation 2, titled Kingdom Hearts Re:Chain of Memories was released along with Kingdom Hearts II