How did Chain of Memories become Re:Chain of Memories?
Kingdom Hearts: Chain of Memories was the series’ first portable game: a Game Boy Advance title released in Japan on November 11, 2004 and in North America that December, telling the essential bridge story between the first two console games through a card-based battle system and 2D sprite art. It was developed with Jupiter, the Picross studio, and it remains the only main-line Kingdom Hearts built around cards and sprites.
The remake, Kingdom Hearts Re:Chain of Memories, was built by Square Enix’s Osaka team and is a ground-up conversion rather than a port: full 3D graphics in the console games’ engine, voiced cutscenes, new cards and sleights, and a theater mode. It was never sold separately in Japan. It shipped on March 29, 2007 as the second disc of Kingdom Hearts II Final Mix+, and the remake is literally what the “+” in that title stands for.
North America, which was never getting Final Mix+, asked for the remake on its own, and Square Enix eventually complied: a standalone North American PS2 release on December 2, 2008, at $29.99 (~$19 in today’s clearance memory, but a full release then). Europe and Australia never received the PS2 version at all; their first Re:Chain of Memories arrived inside HD 1.5 ReMIX in 2013, nine years after the GBA original. The Advance version, with its sprite art and link-cable battles, has never been reissued, which is why collectors treat the two Chains as separate games rather than as versions of one.