Fullmetal Alchemist: Dual Sympathy Character mode
Successfully complete Story mode to unlock Character mode.
Hard mode
Successfully complete Story mode to unlock the Hard difficulty setting.
Sound Library voices
Successfully complete Character mode to unlock that character’s voice in the Sound Library.
Gallery pictures
Successfully complete the indicated task to unlock the corresponding picture in the gallery:
Picture 1-1: Successfully complete the game eight times and select the squares at the end.
Picture 1-2: Have the Game Boy Advance game Fullmetal Alchemist: Omoide No Sonata in the cartridge slot.
Picture 1-3: Have the Game Boy Advance game Full Metal Alchemist: Hagane No Renkinjutsushi in the cartridge slot.
Picture 2-1: Successfully complete Character mode with Ed without continuing.
Picture 2-2: Successfully complete Character mode with Al without continuing.
Picture 2-3: Successfully complete Character mode with Mustang without continuing.
Picture 3-1: Successfully complete Character mode with Armstrong without continuing.
Picture 3-2: Successfully complete Character mode with Scar without continuing.
Picture 3-3: Successfully complete Character mode with Izumi without continuing.
The image featured at the top of this post is ©The Legend of Heroes: Trails of Cold Steel III key art.