Professor Layton and the Diabolical Box Cheats - Nintendo DS
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.
Top Secret Options
Character Profiles - Acquire 2,500 picarats.
Story Art - Acquire 3,000 picarats.
Game Music - Acquire 3,500 picarats.
Character Voices - Acquire 4,000 picarats.
Movies - Acquire 4,500 picarats.