Riddler is a game and puzzle book publisher specialized in creating high quality personalized titles for a variety of audiences. It currently publishes over 30,000 game books that make unforgettable gifts, including a broad array of Sudoku puzzles. Top titles include "The Best Ever Book of Sudoku Puzzles for Dads" , "The Book of Sudoku Puzzles for Sitting on the Loo" , and the popular volume set loved by Sudoku experts; "Hard to Extreme Difficulty Sudoku Puzzles" .

Riddler continues captivate their audience by creating innovative titles that diverge from whimsical gift titles to serious challenges for adept players. It will be expanding to the puzzle market with themed crossword titles, word search games, and all of your other favorite puzzle genres. Riddler's titles are currently available for purchase online and can be found in your local book shop.