All Working Professor Layton and the Diabolical Box Cheats - DS
Hints
Art Gallery
After beating the game, go to the Top Secret section of the Bonuses menu. You'll be able to access an art gallery depicting various scenes from the game.
Character Profiles List
After you've beaten the game, go to the Top Secret section of the Bonuses menu. Inside, you'll be able to access profiles for every character in the game.
Unlock Golden Icons
Golden Layton - Complete the Game.
Golden Luke - Complete all puzzles in the story mode.