Pick the world or a continent, then name every country from its silhouette.
Name every country from its silhouette alone, for the whole world or one continent. Without borders, labels or neighbours for context, you have to know the shape itself: the boot of Italy is easy, the outline of Paraguay less so. If you've done a country shapes quiz on Sporcle or JetPunk, it's the same format. (Geographys isn't affiliated with Sporcle or JetPunk.)
A country's shape comes from history as much as geography. Rivers and ridges make wiggly edges, while straight lines usually mean a border agreed on a map. Coasts give the most away: Italy's boot, Norway's fjords, and Chile, more than 4,000 km long and rarely more than a few hundred wide.
Some shapes only make sense next to a neighbour. The Gambia is a strip along the Gambia River, surrounded by Senegal except at the coast, and Lesotho is completely surrounded by South Africa. The outlines show land only, so big lakes show as gaps: Lake Victoria takes a bite out of Uganda, Kenya and Tanzania.