Normal sudoku rules apply. The pumpkin (orange line) is an entropic line on which each neighbouring group of three cells include one low (1,2,3), one middle (4,5,6) and one high (7,8,9) digit. The stem (green line) is a German whisper, where neighbouring digits have a difference of at least 5. The face is made up of of thermometers, on which the digits increase from the bulb end. Digits separated by an X sum to 10 and digits separated by a V sum to 5.