A picture of a cat or dog is put on the screen and you must chose which one it is in a certain time limit. You start with 2 seconds and every time you get the picture right, you get another second added. You lose when you run out of time or click cat if it is a dog or dog if it is a cat.
Sped up game drastically by reformatting pictures, gave instruction in the top right corner. Changed amount of time you have to make it harder.