How to Play

The goal of the game is simple, draw a single continuous line, the stroke, from one square to another. When you run the puzzle (press F5) white and black squares along this line will flip over (white becoming black, and black becoming white). The puzzle is solved when all tiles on the rows are the same color. You can reset a puzzle by pressing the right mouse button or the F4 key.

Here is a very simple puzzle we will use in this tutorial. As you can see, rows have both white and black tiles. We will try to set them to either all white, or all black.

Let's try a random stroke, just to have a glimpse at how the game works. The squares covered by the stroke are reversed when the puzzle is run.

The first, second and fourth rows would be valid in a solution, as each of them is made up of tiles of the same color. The third row is what caused the puzzle not to be solved: it is made up of both white and black squares.

For some puzzles, setting all the tiles to one color is the simplest solution. Let's do that and draw a stroke that goes over all the white tiles so that when the puzzle is ran all white tiles turn black. Congratulations, we solved our first puzzle!

Note: We could also have turned the puzzle to all white by running our stroke over the black tiles.

The solution found above solved our puzzle with a 14 tiles long stroke. Can we find a shorter, more efficient solution? Remember that the goal of the game is to have only tiles of the same color on each row. Therefore having some rows colored black and the others colored white will work for us too.

Here's a much shorter stroke which also solves the puzzle. This time, our solution has a length of only 4 tiles!