How to play mastermind:
The computer randomly selects a code, the complexity of that code varies according to the difficulty level you have selected. You then have to crack the computer's code. You do this but inputting your own codes then pressing the 'check your code' button; you will then be told how much of your code is correct: black dots indicate that you have the correct colour in the correct position, white dots indicate that you have got the correct colour in the wrong position.
Your score is calculated using the number of attempts you made at cracking the code and the time it took you to crack the code. So to get a good score you need to be quick and efficient.