Layton's Challenges...
	The Diabolical Box Reopened Pu...
	Top Secret Options...

Layton's challenges are the hardest puzzles in the game. They are found under the bonuses section. Each one has a different way of being unlocked.

Challenge	How to unlock
The Puzzle Keeper's House	Complete 165 puzzles.
The Hotelier's House	Beat all ten toy car courses.
The Messenger's House	Complete all 12 parrot delivery errands.
The Storyteller's House	Complete all three picture books.
The Time Traveler's House	Beat the game.

After you've completed Professor Layton and the Diabolical Box, you'll be given a special code. These codes are unique for each DS system. Copy down that code, access the Top Secret bonuses of Professor Layton and the Unwound Future, select the Hidden Door menu, and input the code. You'll unlock the Diabolical Box Reopened Puzzle, an extra challenge that features the antagonist from that game.

Once you acquire enough Picarats, you unlock the following options in the top secret section.

Option	How to unlock
Additional Character Profiles	Solve all 168 Puzzles
Character Profiles	Acquire 4200 Picarats
Character Voices	Acquire 5000 Picarats
Game Music	Acquire 4700 Picarats
Movies	Acquire 5200 Picarats
Story Art	Acquire 4500 Picarats