Type 'easy' or 'hard' to begin the quiz. Easy is a 2-degree grid, hard is a 1-degree grid. A grid will be placed randomly on the map. Then, try to name the 1st-5th largest city in each square, depending on what the square label displays (so if the label says '3rd Largest' you are trying to name the 3rd largest city in that square). To name a city, you must first click on the grid square to make it have a GREEN border. Then, type in the city answer for that square followed by a '.' (a period). You are given a score from 0 to 100 based on your answer's population compared to the target city accepted in that square (100 being you named the correct city).
At the end of the quiz the target city will show in each unanswered square.
Quiz Takers 
need to allow full screen mode and also make the correct marker a different color (currently both are green if you guess close)
Kinda hard to click on phones and tablets but it’s like this everywhere so it’s not that bad
How does the quizz start ?
was a bug – fixed.
why for 0 km you still get 99 and not 100
You can always use the zoom function though admittedly it will make you lose some time zooming in/out and moving the map around. Previous locator quizzes were not timed so it adds an extra challenge.
A little hard to click precisely when places are so close (especially around Paris), but nice quiz.