Phoenix Wright: Ace Attorney Justice for All (Nintendo DS)
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Unlocking all 4 cases (Japanese version only)
Similar to Gyakuten Saiban: Yomigaeru Gyakuten, if you insert Gyakuten Saiban 2 (GBA) in the GBA slot when you turn on "Gyakuten Saiban 2 (DS)" you can unlock all four cases and start on which ever one you want.