Christmas Sudoku is a picture sudoku for kids, with Christmas trees, presents, stars and bells instead of numbers. Put one of each in every row, column and box, starting with small 4 by 4 grids that suit five-year-olds. A snowman and a gingerbread friend join in on the bigger 6 by 6 boards. Play through a snowy meadow, a pine forest, snowman hill, candy cane lane and a twinkly garden under a smiling winter sun, and win a new board for every stage. Every puzzle has exactly one answer, found by thinking, never by guessing, and there is no timer, so children can take all the time they need. It is a calm way to build logic and careful looking, and Wombat is always there with a gentle hint.