Each puzzle consists of a blank grid with clues on the left of every row and on the top of every column. The object is to reveal a hidden picture by painting blocks in each row and column so their length and sequence corresponds to the clues, and there is at least one empty square between adjacent blocks.
There is only one unique solution for each puzzle.
First mouse click fills a square, second mouse click displays a dot to indicate the square is blank and third click brings the square back to its original state. Multiple squares may be filled or blanked by dragging the mouse.