Let's play Outside Sudoku on a 9x9 grid! Outside Sudoku is a variation of the traditional Sudoku grid. Numbers are placed outside the grid, use them as hints to solve the puzzle. This logic based number puzzle game is super fun, kills boredom and is great for taking on the go when you travel by road, plane or train! Help your brain get smarter with this paper based Japanese number puzzle. Outside Sudoku comes in 5 levels: Level 1: Very Easy Vol. 1 - 40, Level 2: Easy Vol. 1 - 40, Level 3: Medium Vol. 1 - 40, Level 4: Hard Vol. 1 - 40 and Level 5: Very Hard Vol. 1 - 40. Collect all 40 volumes of each level and solve them all! Achieve Sudoku greatness!