Deep Spirits

The idea is so simple, so ingenious, that it is hard to believe that nobody thought of it before.
Maybe every great idea feels that way.

I agree great idea. It is simple, but fine in following the primary source of inspiration, which are kids’ drawings.
In the book "The Little Prince", written by Exupery, it is said something that was my first association when following these drawings of Dave Devries:
"One sees clearly only with the heart. The essential is invisible to the eyes."
Kids see under the surface in their clear and not yet contaminated mind. Their simple drawings, essential in presentation but very deep in thoughts, show another world that we have taken as interesting, but never seriously. When transformed into the drawings of adults, these characters transform into the comics heroes.

Those are terrific!