Godoku is similar to Sudoku, but uses letters instead of numbers. The goal of Godoku is to fill in every empty box with one of nine letters. Each letter can appear only once in each horizontal row as well as in each vertical column and in each of the nine 3×3 grids. Some letters are always provided to get you started.
Finally, they also give you a mystery clue to fill in a complete row or column. It is up to you if you choose to use it. Happy Puzzling!