The air gets crisper with Hard Fall Sudoku! This difficult sudoku puzzle level is sure to test your sudoku level to the extreme. You'll need to start using notes in this hard level, if you haven't done so already. To activate sudoku notes click the pencil. You'll notice the squares around the numbers are removed. This denotes you are in sudoku note mode. Enter the number into the space by clicking the number on the sides or using your keyboard. Sudoku games at any difficulty are all played the same way. You must enter the number 1 to 9 into each 3x3 box, column and row only once. Fill out the entire Fall Sudoku board to win this game!