Planarium

In this game, you need to untangle the lines (depict a planar graph). You can play in two modes - without restrictions on the number of clicks on the vertices of the graph and with them. 

Progress in each of the modes is saved independently. In the unlimited mode, there is the possibility of an automatic solution. As you progress through the levels, the graph  complexity grows - in the constrained mode it grows faster!

Sometimes graphs can be generated in an already planar image - this is more likely only at early levels (cause of small amount of number and vertices) - well, a freebie level :) 

Black vertices are not movable (and clicking on them is not taken into account in the mode with restrictions )