The Germany-based browser and mobile game developer InnoGames has generated over $1 billion in lifetime revenue since the studio was set up 12 years ago.

Specifically, VentureBeat reports that InnoGames has surpassed €1 billion in revenue, roughly $1.1 billion. More than half of that, €500 million or $552 million, came from its 2012 release Forge of Empires alone.

InnoGames CEO Henrik Klindworth tells the publication its shift to mobile around 2015 was a difficult adjustment, but one that paid off for the company in the long run as mobile revenue now accounts for half of the company’s take, and mobile games attract the majority of new player registrations.

“One of our biggest challenges was to grow up as a browser game company from the beginning and then enter the mobile market, which was a lot of work and was successful in the end,” Klindworth tells VentureBeat. “We’ve grown both sides of the business. What we have achieved is to build many titles with longevity.”