In the roll-and-write game StegegetS Moomin, you will find many characters from the Moominvalley. As a player, you travel around Moominvalley to visit them on picnics in nature and to collect treasures — jam, marmalade, and such — given to you by them from their earth cellars.

Moomin is a globally famous and loved story world. The plot in these stories often includes excursions and trips in their valley, and this idea was used as inspiration for the story behind the mechanisms in StegegetS Moomin, which centers around a map of the Moominvalley, as depicted in the stories from the 1950s and 1960s.