When it comes to the work of Russian Designer Maria Yasko, one thing comes to mind - fantasy. I really admire her Icelandic Tree shelf from the Vjunok/Bindweed series. It could play very well in a kid's space. She also did another space based on the Moomin books, by Finnish illustrator Tove Jansson, called Moomin Valley. Below is an example of the children's playspace. Quite a fantasy!