The board is a grid of 4x4 cells with different "hidden" pairs of letters, which we have to discover and match.
Click on a cell in the grid to uncover a first letter and then click on another cell to uncover a second.
Two things can happen:
In any case, you must click on two more cells to try to find another pair. Obviously, the game ends when you find all the pairs.
At the top right, the game will show you how many attempts you have made in the current game:
Below the grid you have your best score of all the games you have played.
When you restart the game the letters will be randomly repositioned.