Sudoku
PuzzleWorks on a phone
Play Sudoku online, from easy to evil. Pencil marks, undo, and a hint when one cell refuses to budge, and the rest of the grid is still waiting on you.
Every row, column, and box wants 1 through 9 exactly once. A clash lights up when two of the same digit share a line.
Easy is a clean solve. Hard, expert, and evil are there when you want the grid to fight back.
How to play
Pick easy, medium, hard, expert, or evil. Tap a cell and press 1 to 9, or use the number pad. Notes toggles pencil marks, Undo steps back, and Hint fills the selected cell.
Sudoku by Tom Nick, under the MIT license. The license file sits with the game.