Kingdom Hearts Re: Chain of Memories Cheats

Reverse/Rebirth Mode
To get Reverse/Rebirth Mode where you play through the story as Riku, simply beat the game once as Sora.

Reverse/Rebirth Mode: Beat the game as Sora.

Theatre Mode
Beat the game once to unlock Theatre Mode, an extra option on the main menu wherein you may re-watch any cutscene in the game.

Theatre Mode: Beat the game.

Secret Card in Sora's Story
Beat Sora's story and unlock reverse/rebirth mode. Go back to Sora's story and the Ansem card will be in a chest in Castle Oblivion.

Roxas Card
Roxas card (Doubles attack strength): Go to Twilight Town in Sora's mode and enter the treasure room. There should be two chests with one of them containing the Roxas card.

Special Cards
Ansem: Beat Reverse/Rebirth mode and obtain from a chest in Castle Oblivion.
Diamond Dust: Beat Riku's story and obtain from a chest in Castle Oblivion.
Getting Mushu and Xigbar card: Go to Hollow Bastion and use key of rewards and there will be two chests one containing Xigbar.
Lexaeus: Beat Reverse/Rebirth mode and obtain from a chest in Castle Oblivion.
One Winged Angel: Beat Riku's story and obtain from a chest in Twilight Town.
Roxas card (Doubles attack strength): Go to Twilight Town in Sora's mode and enter the treasure room. There should be two chests with one of them containing the Roxas card.
Ultima: Beat Riku's story and obtain from a chest/shop in Castle Oblivion.
Zexion's Card: Beat Riku's story and retrieve from a chest in Destiny Islands.