Mahjongg Master Game System: Nintendo 64 Cheat Category: Cheat Game Company: Unknown Game Category: Unknown Hint, Cheat, Walkthrough:   Mahjongg Master =============== Unlock all Characters: (submitted by: Thomas OCampo) While the opening movie is playing enter this code: Up, Up, Down, Down, Left, Right, Left, Right, B, A, Start. When you open the Free Battle Kulong Mode, all 19 characters will be usable.