You will be given a random number goal 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 win the game by exactly matching your total score to the goal score. You lose the game if your total score goes above the score goal.
The value of each crystal is hidden from you until you click on it. The values of each crystal and the score goal will change with each new game.