Following on the heels of Jumbo Sudoku Easy, Jumbo Sudoku Challenge includes 400 all-new puzzles to test sudoku enthusiasts. This collection contains some of the most difficult puzzles available and is sure to entice die-hard sudoku solvers. Jumbo Sudoku Challenge also includes Killer Sudoku – a different way to get your Sudoku fix - along with the regular puzzles ranging in levels from difficult to the absolute fiendish. Every puzzle is an oversized grid so you have extra room to help you solve. Plus as a bonus, Jumbo Sudoku Challenge will feature a special pull-out Shogun puzzle – it is the ultimate Sudoku test!