From the designers‘ website:
"The Gold Trilogy" covers the games The Golden City, Valdora and Felinia. All three games are linked by a thematical gameworld in which they take place: a kingdom (Felinia), a valley (Valdora) and a city (The Golden City). Other links are: gold (of course!) which has a more or less important role in each game and other aspects like the provisions in Valdora and Felinia which are part of the movement systems.