Welcome to the world of really big Sudoku puzzles for iPads. Sudoku Behemoth features one hundred original 20x20 logic games that will provide countless hours of mental exercise. This app has the same rules as standard Sudoku, with the exception, of course, that the applicable numbers are in the range from 1 to 20. There is a timer for each puzzle that records the completion time for that puzzle and, via Game Center, for selected puzzles you can issue challenges to your friends as well as enter your times on leaderboards.

Here's how it works: as with standard Sudoku, for each puzzle Sudoku Behemoth provides a partially completed board and you must provide the numbers to finalize it. As you enter each number, you will receive instant feedback for the current status of the puzzle - White indicates the entry is OK whereas Red indicates an error. It is very important to note, however, that the provided status is for the condition of the game at THAT PARTICULAR POINT IN THE COMPLETION OF THE PUZZLE, which is to say, it reflects the status for the combination of the pre-supplied numbers and the entries you have provided. Just because a number is White does not mean it is the final answer for a certain square, just as a Red entry does not mean is incorrect for the final answer - an entry can be Red because of another entry you have made elsewhere. As always, the challenge is for you to think!

Instructions are available on each screen, so please feel free to tackle Sudoku Behemoth and enjoy.