Hypersudoku

You’ve got a grid of 9 x 9 squares. Your task? Fill in each square with numbers 1 – 9 so that the numbers in each row, column or 3 x 3 group do not repeat. The 9 groups are surrounded by thick lines. This game is similar to sudoku, except that there are extra 3×3 regions where the numbers must not repeat. The faster you finish the game, the higher your score. Click the hint button when you are stuck, but you will suffer a time penalty when you do so. Have fun with Hypersudoku!