If the game freezes, just click inside it (games can get unresponsive if you click elsewhere on the page).
Use your memory to find pairs of cards. Naruto and his ninja friends are on the cards. You can find, then, Sakura, Sasuke, Kakashi, Minato, Kyubi, Itachi and many others. Post your score once you finish the game. The difficulty increases with the levels and you will have sixty seconds to find each pair.
Use your mouse to return each card.