At the start of the game, the target number will be displayed
There are four crystals. By clicking on a crystal, you will add a specific number of points to your total score
You win the game by matching your total to the target number. You lose the game if your total score goes above the target number
The value of each crystal is hidden from you until you click on it.
Each time when the game starts, the game will change the target value and the value of each crystal.