Test your visual acuity by trying to find the differences between two very similar pictures. Each level presents you with two pictures side by side. They are the same in almost every way. Each group of pictures has four differences that you have to reveal to win. When you find a difference, click on it on either side of the two pictures. You will see it flicker, and the pictures will change to be the same on both sides. After completing a level, you move to the next set of pictures. There is no penalty for clicking on something that's not a difference, so feel free to try!