To start the game, wait for it to load and then click Play. You need to find 7 differences for 180 seconds (3 minutes). Cope with the problem - you can move on to a new level button ( Next Level) - find differences between the next pair of images.
For each found the difference you get 100 points. For the error (click to the point where no differences) deducted from your account 5 points.
If you deal with the problem quickly, you get bonus extra seconds to solve the following problem. If you have difficulty with problem solving, every 60 seconds you are given the hint! (there is a button Hint - click on it.)