This great gamebook contains hard to extreme level for Sudoku puzzles game suitable for the Pros of Sudoku puzzle lovers. - 224 hard to extreme games with answer provide at the back of the book. - 2 big puzzles on each page give you wide space to note. - Large print on white paper. - Size 8.5x11 similar A4 size but shorter in height. - A GREAT GIFT: For the sudoku puzzle lover, for any occasion! Birthday, stocking suffers, road trip or more, everyone will love it! Let's start to enjoy this Sudoku simple for your brain gym and have fun.!!