As its name implies, this game is actually a WindowsPhone 7 version of the highly popular Sudoku number puzzle, originally created by Howard Garns back in 1979.

Here are the rules:

Fill the grid so that the numbers 1 through 9 appear in each row.

Fill the grid so that the numbers 1 through 9 appear in each column.

Fill the grid so that the numbers 1 through 9 appear in each 3x3 box.

A complete Sudoku puzzle contains the numbers 1 through 9 in every row, column, and 3x3 box.