At White Nights 2014 Anastasios Katopodis, the producer of Rovio, told an interesting fact: initially Angry Birds: Epic was a third-party project that Rovio was offered to publish.
In 2012, small German developers Chimera came to the Finns with a concept (video concept) of a game with turn-based battles in a fantasy style very close to Castle Ville.
Rovio really liked the project, but they refused to publish it. Their suggestion was as follows: make this game, but in the Angry Birds setting.
The creation of the project took two years.