Sudoku-Classic Sudoku Puzzle is a popular and addictive brain Sudoku puzzle game. More than 1200 challenging Sudoku puzzles, suitable for beginners and advanced players brain Sudoku! There are 4 difficulty levels-Simple Sudoku, Medium Sudoku, Hard Sudoku and Expert Sudoku! Pencil mode-Turn onoff the pencil mode as needed. Highlight repetition-Avoid repeating numbers in rows, columns, and blocks. Smart tips-guide you through the numbers when you encounter difficulties. Undo-return to the last operation. Theme-Choose a theme that makes your eyes easier Use dark mode to protect your eyes.