ZeptoLab has had spectacular success, getting 600 million downloads for its mobile games based on Cut the Rope, a physics-based game with the adorable Om Nom. And now the studio’s branching out to hardcore gamers with a new mobile game, King of Thieves.

Two years in the making, King of Thieves is for the midcore audience, or those who like hardcore games that are playable in short game sessions. It’s a big stretch for the Moscow-based ZeptoLab as it searches for new markets, but the company has to find another magical franchise that will keep its players coming back. Clearly, ZeptoLab has been busy creating new games even as it works on Cut the Rope sequels. This app combines platform play and dungeon defense in the same game and has a cartoon art style, which could also be appealing for fans of Cut the Rope.

“Our entire company has been focused on doing something new,” said Misha Lyalin, the chief executive of ZeptoLab, in an interview with GamesBeat. “It’s a big challenge for us, but we have gotten to a game that we are proud of. It has been a big challenge for us.”

King of Thieves launches as a free-to-play multiplayer game on iOS this February, and it’s the first in a series of original apps coming from ZeptoLab this year, Lyalin said. ZeptoLab plans to work with third-party studios to bring externally developed works to the market as well.

“We don’t know of any game that is like King of Thieves, but it’s hard to say if it will be considered a new genre,” Lyalin said.

King of Thieves

Above: King of Thieves

Image Credit: Zeptolab

King of Thieves, players run and jump to dodge deadly traps, compete to break into each other’s customizable dungeons, and accumulate enemies’ gems and gold in asynchronous gameplay. Lyalin said it tests players’ fingers as well as their brains. This kind of asynchronous gameplay is similar to the No. 1 game in the mobile world, Clash of Clans, where you attack someone else’s base while that person is offline.

Since 2008, the company has grown from two brothers in Moscow to more than 100 employees. Semyon and Efim Voinov created Cut the Rope, which debuted in 2010. It became an enormous hit, and it has spawned several sequels already.

But ZeptoLab won’t be able to rely on Cut the Rope forever.

“We are ready to show the world what we have produced,” Lyalin said.