Welcome to The Penguin Sudoku Challenge: with 1 sudoku puzzle for every day of the year 2 challenge you in every way on 3 different levels - beginner, moderate and fist-clenchingly tricky.Perfect 4 sharpening your brain and honing your logic, sudoku will give you a 5 star brain (if they don't hit you for 6).In 7th heaven when you complete them, you'll 8 giving up on any of these - but those 9 by nines won't complete themselves...Good luck!