Sudoku is the martial art of puzzles, so keep your mind fighting fit with this collection of energetic enigmas and numerical conundrums. Choose from games such as the Swordfish, the Gordonian Polygon, Alternating Digits and Jellyfish which make these sudoku ninja-hard! Its handy format means it's also perfect for solvers on the go and because it is easy-to-learn, addictive and language free, it's suitable for anyone and everyone! Endlessly challenging, these ultimate puzzles will provide hours of fun!