Pause the game and press Start + Select.
Rescue the other two players and finish the game. If done correctly, the phrase "You've got the special key" will appear after the credits. Save the game. Start the game that was just saved. Enter the room with the large mirror on the second floor of the mansion. Unlock the door in the back. Enter the closet and move all the way to the end of the rack of clothes. Then, a message asking "There is an outfit that fits you perfectly, do you want to put it on?" will appear. Now select "Yes" to change your character's clothes. Note: When playing the game with the "Arrange" option, your character will not have the key, but the door will be unlocked.
Finish the game on advanced mode as either character in any amount of time. Then the Magnum, with infinite ammo will be available when the game is replayed.
Finish the game in under three hours without rescuing anyone. If done correctly, a rocket will appear after the credits. Then, choose to continue playing after the game restarts. Now the rocket launcher with infinite ammunition will be available when the new game begins. Note: The rocket launcher does not shoot well upwards or downwards.
On the game mode screen, highlight the "Arrange" option and hold Right until the pointer turns green. Then, begin a game and double the normal amount of items, including ink ribbons and ammunition, will be available.
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