Clicker - The Rules
Clicker is an interactive game that combines both the interactivity of action games and the 'brain power' of the more relaxing, no time-pressure games. Now and then, a number will appear for a short period of time, and after that it will disappear. The objective of the game is to click on all numbers that are perfect squares (like 121, which is 11 * 11), and to ignore the other ones.
The numbers that will appear are in the range 0 .. 200, so there is a limited pool of perfect squares that you have to recognize. However, the time allocated for evaluating and then clicking / ignoring the number is limited. You are allowed to make 5 mistakes. The final score is the count of numbers for which you took the correct action.