9x9 Sudoku Game

Sudoku is a logic-based, combinatorial number-placement puzzle. The objective is to fill a 9x9 grid with digits so that each column, each row, and each of the nine 3x3 subgrids (also known as boxes or regions) contain all of the digits from 1 to 9 without repeating any numbers.

Basic Rules

• Fill each empty cell with a number from 1 to 9
• Each row must contain all numbers from 1 to 9
• Each column must contain all numbers from 1 to 9
• Each 3x3 box must contain all numbers from 1 to 9
• Pre-filled cells cannot be modified

Controls

• Click any empty cell to select it
• Use number buttons or keyboard (1-9) to input numbers
• Use Erase button or Backspace key to remove numbers
• Click "Check Solution" to verify your answers
• Click "New Game" to start a fresh puzzle

Scoring System

• Starting score: 100 points
• Correct number: +1 point
• Incorrect number: -1 point
• Time penalty: -5 points every 30 seconds
• Game ends when score reaches 0

Visual Feedback

• Green numbers: Correct placement
• Red numbers: Incorrect placement
• Gray numbers: Pre-filled cells (fixed)
• Blue highlight: Selected cell

Game End

• Game ends when you click "Check Solution"
• Game ends when your score reaches 0
• Submit your score to the leaderboard
• Complete quickly for a better score!