Halloween Sudoku: how to play

Halloween Sudoku is a free picture sudoku online, hosted by Luna, a sleepy crescent moon who stays up just to play. The first grids use Halloween pictures instead of numbers: pumpkins, bats, moons and ghosts, then candy and owls too. After that the numbers come out for three 9×9 sudoku grids, from the Pumpkin Patch all the way to the Star Castle. Every grid has exactly one answer, so you never need to guess.

How to play

To play Halloween Sudoku, fill every row, column and box so each picture (or number) appears once. The pictures and numbers already on the grid are your clues.
Tap a square, then a picture or number on the pad under the grid. Keys 1–9 and the arrows work too: on the picture grids, 1 is the pumpkin, 2 the bat, 3 the moon, 4 the ghost, 5 the candy and 6 the owl.
Switch to NOTES (or hold Shift) to pencil in maybes. Placing a picture or number tidies it out of your notes in the same row, column and box.
A wrong answer costs one of your three hearts and doesn't stay on the grid, so you can think again.
Solve a grid for 100 points × the level number, plus a speed bonus. Three stars per level: solve it, solve it without losing a heart, and solve it under the target time.

The five levels

Pumpkin Patch: 4×4 picture sudoku with a pumpkin, a bat, a moon and a ghost
Candy Lane: 6×6 picture sudoku with candy and owls too; the boxes are 3 wide and 2 tall
Owl Woods: the numbers come out: an easy 9×9 sudoku
Moon Hill: 9×9 with fewer clues: find the only square a number fits
Star Castle: the toughest 9×9: a pair in your notes rules out other squares

Clear Star Castle and the levels loop again as hard 9×9 number grids, with fewer numbers given each time, down to 24. You have three hearts for the whole run, and the game is the same for everyone each day, so you can compare scores. Press M to turn the sound off or on.

Tips

On the picture grids, look for a row, column or box that is missing just one picture.
Say the pictures to yourself: "pumpkin, bat, moon… so this one is the ghost."
On the 9×9 grids, pick a number and look for the only square in a box where it can go.
When two squares in a box can only hold the same two numbers, those numbers are ruled out everywhere else in that box.

Questions

Is Halloween Sudoku free?

Yes. Halloween Sudoku is free online in your browser, with no download and no sign-up.

What is picture sudoku?

Sudoku with pictures instead of numbers. The rules are the same: every row, column and box holds each picture once. Here the 4×4 and 6×6 grids use Halloween pictures and the 9×9 grids use numbers.