Professor Layton and the Unwound Future Cheats

Layton's Challenges
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.

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.

Layton's Challenges
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.

The Puzzle Keeper's House: Complete 165 puzzles.

The Diabolical Box Reopened Puzzle
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.

The Diabolical Box Reopened Puzzle: Complete Professor Layton and the Diabolical Box to obtain a code, then input the code in the Hidden Door menu of the Unwound Future.