This game is based on the principles of logic. The game uses numbers and special characters to test your logical thinking, and puzzle solving skills. Improve your Memory & Concentration, Self Esteem, and Problem Solving Skills. See for yourself how SUDOKU can be your favorite pass time game. Install now for FREE! New Features: - Beat the TIME Sudoku - Challenging 12 x 12 Puzzles is available NOW! How To PLAY: To solve Ultimate Sudoku puzzle, every number from 1 to 9 must appear in: ★ Each of the nine vertical columns ★ Each of the nine horizontal rows ★ Each of the nine 3 x 3 boxes In ULTIMATE SUDOKU puzzles, you have additional characters, as well the numbers 1 to 9 that must also appear in: ★ Each of the twelve vertical columns ★ Each of the twelve horizontal rows ★ Each of the nine 3 x 4 boxes Features: ★ Unlimited Sudoku puzzles ★ Fun puzzle game-play ★ Choose Your Difficulty Level: Easy, Moderate, Hard ★ Automatic or Manual Pencil Marks ★ Undo and Redo Function ★ Perfect for Tablets and Phones ★ Free & easy to play ★ Play OFFLINE in anytime and anywhere with no time limits ★ Beat the TIME Sudoku ★ Play NEW Challenging 12 x 12 Puzzles Start Your Daily Brain Training NOW! Ultimate Sudoku