You will be given a random number at the start of the game.
There are four crystals below. By clicking on a crystal you will add a specific amount of points to your total score.
You will win the game by matching your total score to the random number. You lose if your total score goes about the random number.
The value of each crystal is hidden from you until it is clicked.
Each time a new game starts, the game with change the random number and the value of the crystals.