Super Quadoku

A four-by-four version of sudoku using both numbers and colors for an added challenge. The numbers from 1 to 4 cannot repeat in any row, column, or quadrant. Similarly, the colors red, blue, green, and yellow cannot repeat in any row, column, or quadrant. With the touchscreen, the user may select and drag any of the number or colors from the input palette, and drop or paste them into the game squares. Alternatively, once an input tile is selected by either tapping or dragging, it display highlighted and will remain the active selection. The user can then tap a game square to enter the active selection into the grid, which can save time if more than one square can be filled with the same item. Points are awarded for each input, with greater points being awarded for shorter elapsed time between moves. Points are deducted for input errors or for using the 'undo' button. The maximum possible score is 500.