An interesting game with the nice interface and the rule is very easy to play.
There are 4 levels of difficulty as Beginner, Easy, Normal and Hard. And whichever level you wanna try, the best advice is choosing showing and counting time in Settings first then go to Play!
In Harder levels, more showing and counting time you need!
When the showing time ended, you need to give out the numbers of Christmas balls before counting time go to zero and touch out of keyboard area, your answer will be accepted and you will see the result that shows you were right or not.
Playing this game helps you to improve your abilities of observation, remembering, assertiveness...
Let's try and enjoy it!