This game measures your search and response abilities.
you should tap on 1 to 20 . each correct selection has 1 positive score and each wrong answer has 2 negative scores.Also it has Bonus on number 5,10,15 and 20 if you meet the time which is different in each individual level.
MAX scores are:
EASY : 59
MEDIUM : 257
HARD : 10075
However nobody can reach these scores , because humans have some limitations ;Albeit, you can improve your score in each level close to these numbers:
EASY : 50
MEDIUM : 150
HARD : 2000
Good Luck !