You are going to guess the four numbers generated randomly from 0-9. Each time you guess, you will be given some feedback regarding your guess, represented as Solar and Moon. The Solar number indicates how many numbers you guessed are correct and their positions are also correct; The Moon number indicates how many numbers you guessed are correct but their positions are wrong.
You try to improve your guess according to feedback, until your guessed numbers are all correct and their positions are correct. Finally you will be ranked depending on the time(in second) you used and how many guesses you made before getting the answer. You can submit your rank onto global score board and compete with other players around the world!