What it is like
Euclidea gives you a line, a circle or a point and asks you to construct something exact: a perpendicular, a tangent, a square inside a circle. Your only tools are the ones the ancient Greeks had, a straightedge and a compass, and each puzzle can be solved in a set number of moves.
It is quietly addictive in the best way, because each level is a small, finished thought. The first packs teach the basic moves; later ones ask you to combine them cleverly. Solving a level in the fewest moves earns extra stars, which turns an easy level into a real puzzle the second time round.
Your first go
Start at the first pack even if you know your geometry; the early levels teach the tools you will need. When you are stuck, step away for a minute rather than trying moves at random.
A good place to stop
Every level ends when the construction is done. Decide on a number of levels before you start, three is plenty, and stop there even if the next one looks easy.
Before you click
The web version is free without limits on stars. On phones and tablets, later packs unlock with stars you earn or with an in-app purchase.
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