The castle-model-viewer icon (created together with old Castle Game Engine icon) are
Copyright 2008-2018 Katarzyna Obrycka, Michalis Kamburelis.

Distributed on GNU GPL >= 2 license,
just like the castle-model-viewer code itself.

Kasia Obrycka did the most important work of making the icon actually "work",
by providing moon, tentacles and idea to shade the tower. Thanks!
