The next instalment in the popular "Jumbo Sudoku" series, "Jumbo Sudoku Hard as Heck" includes over 300 puzzles. The popular numerical brainteaser is a fun way to work the brain, and Sudoku fans of all levels will love this collection. "Jumbo Sudoku Hard as Heck" includes classic Sudoku, as well as samurai, Kukoro, Killer, and "Son of Sudoku", Futoshiki puzzles. All the puzzles are rated on a scale of hard to fiendish. If readers are looking to finally be challenged by Sudoku, this is the book they have been waiting for. Sudoku puzzles continue to run in top newspapers and magazines across the country. Because every puzzle is completely different, Sudoku appeals to puzzle-fans of all ages.