EXCALIBUR ET453 Einstein Touch Sudoku. Sudoku is the hottest game going. Einstein Pocket SuDoku contains more than 800 puzzles, all easy to work with the included stylus. It has an ergonomic, lightweight design. It allows you to saves game in memory. You can choose from easy, medium, or hard puzzles so you can play at your pace. It also comes with a hint key in case you get stumped.