an ideal game for those cold winter nights, based on the principles of good visualization of traditional vertice-edge network diagrams. players can click on the blue dots (vertices), & drag them around. one should then try to arrange the vertices so none of the lines (edges) intersect, so that a new level will appear.
once several levels have been mastered, you can always apply your new skills on the vizster or the enron email networks. [planarity.net]