🧩 Sudoku

🧩 Sudoku

Objective: Fill the 9x9 grid so each row, column, and 3x3 box contains digits 1-9 exactly once.

Controls:

• Click a cell to select it, or use arrow keys
• Press 1-9 on keyboard or click palette buttons
• Press Delete/Backspace or click X to clear
• Press N to toggle Notes mode for pencil marks
• Press H or click Hint to reveal a cell
• Press Ctrl+Z or click Undo to revert
• Use arrow keys to navigate the grid
• Press P to pause/resume

Rules: Each row, column and 3x3 box must contain all digits 1-9 exactly once. Conflicts are highlighted in red. You have limited errors based on difficulty (3-5).

Tips: Use Notes mode to pencil-mark candidates in each cell. Look for naked singles (cells with only one candidate). Use cross-hatching to eliminate candidates. When stuck, take a break or use a hint.

Scoring: Base score 2000. Time bonus decreases as time increases. Hint bonus (150 each remaining). Error penalty (100 each). Difficulty multiplier (Easy x1, Medium x1.5, Hard x2).