Great interactive tool to teach the distortions of the Mercator Projection

Some wonderful people have made an interactive puzzle that wonderfully demonstrates how the Mercator Projection distorts size towards either pole. You start with 15 red countries scattered across a Mercator Projection of the world. A detail of the initial screen:

Mercator Puzzle -- click for the actual puzzle

Click on the image for the actual puzzle!

Move each red shape around the map until it coincides with the actual country; once "fitted" to the projection, the shape turns green:

Mercator Puzzle partially completed

Click on the image for the actual puzzle!

Note that it's easier to do this with a computer, using a mouse, rather than on a tablet, with a finger or stylus. Also, it works only with the same 15 countries.

Enjoy!

h/t Donna Genzmer at UW-Milwaukee