Playing Samurai Sudoku is not just a fun way to pass the time, due to its logical elements it has been found as a proven method of exercising and stimulating portions of your brain, training it even if you will and just like training any other muscle regularly you can expect to see an improvement in cognitive functions. Some studies go as far as indicating regular puzzles can even help reduce the risk of Alzheimer's and other health problems in later life. This Samurai Sudoku Logic Puzzles book is packed with the following features: - 500 Hard Sudoku puzzles overlapping into 100 Samurai style. - Answers to every puzzle are provided at the back of the book. - Each puzzle is guaranteed to have only one solution. - One puzzle per page (8.5 x 11 inches) and large print font for the prevention of eye-strain. - Includes free bonus puzzles you can download book (Tons of Sudoku Puzzles for Adults & Seniors) - Includes free bonus puzzles you can download book (Word Search With Hidden Message: 102 Puzzles for Adults and Seniors)