The sea is two puzzles in one. Coral reefs and rock pools are riotous and easy, full of colour and shape. Open water is the sternest test in this whole library — a stretch of blue can give you fifty pieces that differ only in the faintest gradient, solvable by shape and patience rather than sight. Choose deliberately depending on which evening you are having.
Choose carefully here, because this category contains both the easiest and the hardest pictures on the site. A rock pool or a reef is dense with detail and very forgiving. Open water is close to a blank field, and a seascape that is half sky and half sea has two of them stacked. If you want the challenge, take it deliberately rather than by accident.
Difficulty: Ranges from very easy to genuinely hard. Check the badge first. Every picture here is graded automatically by how much its neighbouring pixels differ, rather than by subject — why that is the thing that matters.
Pick any picture below, choose anywhere from 12 to 2000 pieces, and play free in your browser. Share one link to solve it with friends on the same table, or use a photograph of your own instead. Browse every category.