Type 'easy' or 'hard' to begin the quiz. Easy is a 2-degree grid, hard is a 1-degree grid. Then, try to name the largest UK 1K+ cities in each square IN ORDER. 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).
The squares will start with '0/5' (or maybe fewer cities if less exist in that square). Click on a square and enter the largest city in that square not yet answered (so, the largest city if you have yet to answer a city in that square). You will then have '1/5' and need to click on that square to name the 2nd largest city, and so on until you complete all the cities up to 5 (or less if less exist). If you name an incorrect city in a square it becomes 'locked' and turns red and you can no longer accumulate cities in that square.
You receive 1 point for the largest city in a square, 2 for the 2nd largest, and so on.
At the end of the quiz the largest remaining city you haven't named will be shown in each square.
Quiz Takers 
I think that Saint Petersburg shouldn’t be on here (since it’s 15 letters). And in the “50 hardest” West Bromwich is listed twice
for ‘Saint’ i went with ‘St’ for countries where that is the typical spelling (via the country’s census/Wikipedia/other references to the city) – so for US/Russia and a few others it is ‘St’ whereas French/etc it is ‘Saint’ and other countries may be something like ‘Sankt’.
okay, though I’m pretty sure St. is not a typical spelling in Russia (since Russian doesn’t even have a St. abbreviation)
How long are you going to continue with this series?
If the US series is anything to go by, 14 letters… then a Long Names one for everything beyond that.
yeah long names coming soon for the balance, maybe one more 13-letter one.