Unlock the following options at the "Top Secret" menu by performing the corresponding tasks:
OPTION - HOW TO UNLOCK Additional Character Profiles - Solve all 168 puzzles. Character Profiles - Collect 4,200 Picarats Character Voices - Collect 5,000 Picarats Game Music - Collect 4,700 Picarats Movies - Collect 5,200 Picarats Story Art - Collect 4,500 Picarats
Unlock the following Layton Challenge puzzles in the "Bonuses" menu by performing the corresponding tasks:
CHALLENGE PUZZLE - HOW TO UNLOCK The Hotelier's House - Complete all ten toy car courses. The Messenger's House - Complete all twelve parrot delivery errands. The Storyteller's House - Complete all three picture books. The Time Traveler's House - Complete the game. The Puzzle Keeper's House - Complete 165 puzzles.
Complete Professor Layton And The Diabolical Box to receive a system-specific code. Enter the "Top Secret" screen in Professor Layton And The Unwound Future and choose the "Hidden Door" option, then enter the code.