Angry Birds dev Rovio has acquired the free-to-play mobile game developer Darkfire Games for an undisclosed sum, and rebranded the studio as Rovio Copenhagen.

The acquisition brings all 20 members of Darkfire Games’ staff into Rovio Copenhagen, and previous studio head Rune Vendler will continue to lead the team following the deal.

On the day-to-day, Rovio Copenhagen will continue work on Darkfire Heroes, the soft-launched RPG acquired alongside the studio, but now with access to Rovio’s user acquisition, technology, analytics and live operations resources.

"We are very excited to have Darkfire Games joining Rovio's network of game studios," reads a statement from Rovio CEO Kati Levoranta.

"This strengthens our game genre mastery and expansion to Mid-Core games, where we see attractive opportunities in RPG's. In addition, there is a great strategic and cultural fit for both teams. The talented team in Copenhagen will be a fantastic addition to Rovio's already highly skilled flock."