Ruler of the Plane is a set of games illustrating concepts from combinatorial and computational geometry. The games are based on the art gallery problem, ham-sandwich cuts, the Voronoi game, and geometric network connectivity problems like the Euclidean minimum spanning tree and traveling salesperson problem.
The games are implemented using C# in the game engine Unity.
On https://kbuchin.github.io/ruler/ you can also play the WebGL version of the game (and branches).