Upon clicking START you will be given a flag at the top of the grid of all flags of countries which border at least one other country. Given the country flag, double-click on the flag of the country that the given country’s flag has the longest border with. For example, if you get the US flag at top, you are trying to double-click the flag of the country with which the US shares the longest border. You get 100 points for getting that country correct, and less than 100 for any other bordering countries based on how long that border is compared with the longest.

You only have 5 minutes to get all 25 countries.

Borders are land borders only, including causeways but not including only man-made structures. Borders include dependent territory borders.