Let's Play Sudoku on a 16 x 16 grid! This logic based combinatorial number puzzle game is super fun, kills boredom, great for taking on the go when you travel by road, plane or train! Help your brain get smarter with this paper based puzzle. Comes in 5 levels: Level 1: Super Easy Vol. 1 - 40, Level 2: Easy Vol. 1 - 40, Level 3: Medium Hard Vol. 1 - 40, Level 4: Super Hard Vol. 1 - 40, Level 5: Extremely Hard Vol. 1 - 40. Collect all 40 volumes of the each level and solve them all! You'll be on your way to Sudoku greatness!