Sudoku

You control nothing but the cursor. Your task is to complete the nine-by-nine grid so that each row, column, and three-by-three block contains the digits one through nine without repetition. You click a number from the side panel, then click an empty square to place it. The game often includes basic aids, like the ability to pencil in small notes for potential candidates. The puzzles start gently but can become quite demanding, requiring careful logic and pattern recognition. It feels like a quiet, focused exercise for the mind.