The Legend Of Zelda: The Minish Cap Codes -

Continue game:
Successfully complete the game and allow the credits to end. Save the game when prompted. Your cleared saved game file will be denoted by a triangle. When this file is loaded, you can continue playing, and defeat Vaati again if desired.

Mirror shield:
Load a cleared saved game file, then go to Veil Springs. Fly to Veil Falls and climb up to see Biggoron. He will ask to eat your shield. Agree, then leave the area. Return to him after some time and he will give you the Mirror Shield.

Sound test:
Load a cleared saved game file. There are now six more figurines to collect. Collect all 136 figurines to get the Carlov Medal. Go to the man sitting next to Mama's Café and show him the medal. You can now enter a house that has a robot on the top of it. It contains the sound test, 600 rupees and a Heart piece.