The Brain Boosting Sudoku Loco Craze Very Hard Puzzles with 200+ Challenges, Paperback/Puzzle Therapist

Keep your mind sharp and young by playing Sudoku. You will like the game because it does not require any sort of knowledge beforehand, and you can play it on your own pace. The set of instructions also remain the same regardless of the level of puzzle complexity. Unless there's little competition, Sudoku can be a relaxing and edutaining game that you can play any day.