The goal of Hyper Sudoku is to fill in the empty cells, one number in each, so that each column, row, and region contains each number exactly once. Furthermore, Hyper Sudoku contains four colored regions, each colored region contains each number exactly once. Solving Sudoku is a lot of fun and very easy to learn. Have fun with this Sudoku book! You will find 500 Puzzles to solve. All the puzzles are challenging and entertaining. If you are looking for something unusual and challenging, try the Hyper Sudoku and enjoy! Why Our Book Is A Great Pick: High Quality and Relaxing Puzzles Great for Advance Level Solvers 6 x 9 inches Makes a Wonderful Gift Idea Solutions Included Satisfaction Guaranteed! Kws: sudoku puzzle books, sudoku extremely hard, sudoku puzzles hard, hard sudoku books for adults, hardest sudoku puzzle books