Sudoku ++

Sudoku is puzzling players all over world. Sudoku is easy to learn but a challenge to master.
There is really only one rule to Sudoku: Fill in the game board so that the numbers 1 through 9 occur exactly once in each row, column, and 3x3 box. The numbers can appear in any order and diagonals are not considered. Your initial game board will consist of several numbers that are already placed. Those numbers cannot be changed. Your goal is to fill in the empty squares following the simple rule above.
There are two modes in this game: random mode and level select mode. Using random mode, a new game will be generated randomly and each one will be different. And select mode have five difficulty grades, and each level have about 60 levels.
When Pencil button is enabled, you can put the number which you think is the right one in the unit, and if Pencil button is unabled, you can put the hind number in the unit.
When you exit this game, the level you are playing will be saved automaticlly, and you can redo it using “resume game” button in main menu.