About INSET
Almost every map you have ever seen is a Mercator, and Mercator stretches everything away from the equator. It is why Greenland looks the size of Africa when Africa is about fourteen times larger, and it is why most people's sense of how big a country is turns out to be badly wrong. INSET is built on that one distortion: five rounds a day, each a real continent with a foreign country dropped onto it at the wrong size, and your only move is to scale that country until it looks right.
Every map is drawn in an equal-area projection, so a shape covering twice the pixels really is twice the area. Drag up to grow the country, down to shrink it, or pinch. Submit and it eases to its true size on the map.
Scoring
A round scores 1000 × exp(−|ln(area ratio)| / 0.4), where the ratio is what you guessed over the truth. Getting it exactly right is 1000; being out by a factor of two costs you about four fifths of the round. Over- and under-shooting by the same factor are penalised the same. Five rounds, so a perfect day is 5000.
Every day visits all five continents, one round each, running from easy to hard and ending on a Mercator trap, such as Greenland over Africa, or something like it. Mainland and nearby islands only; scattered overseas territories are left out.
Credits
Country outlines. Natural Earth, public domain. No permission or attribution is required to use it, but it is made by volunteers and worth crediting anyway.
Projection. an azimuthal equal-area projection, centred once per continent, computed offline and baked into the page as plain coordinates. Nothing is projected or fetched at play time.
Type. Space Grotesk, SIL Open Font Licence.
Roadmap
More countries in the pool, so the same five don't come round too often. Smaller map frames, so countries under 25,000 km² can appear at all. There is one puzzle a day and there are no extra rounds, which is the point of a daily.