If the game freezes, just click inside it (games can get unresponsive if you click elsewhere on the page).
Here is a cool game for you to test your concentration abilities by finding the differences between two pictures. Carefully look at these pictures that seem identical but, in fact, they are not, and find all the differences between them before the time runs out. Pay attention to small details and you will realize that the pictures are not quite identical, point the differences to make them vanish to get to the next level and gain points! Do not point on identical details because you will loose points!
This game is played with mouse only.