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Finnish mobile game maker Supercell tripled sales and doubled core profit last year on the back of hit titles Clash of Clans, Hay Day and Boom Beach, the company said on Tuesday.

The Helsinki-based business, which is majority owned by Japan’s SoftBank, said operating profit rose to 515 million euros ($564 million) from 243 million in 2013, while revenue jumped to 1.545 billion euros from 519 million euros.

Chief Executive Ilkka Paananen said in the statement that the rapid growth was thanks to users’ increased play of the company’s existing games, which it updates regularly with extended story lines and features.

“Our goal is to do games that people could play for years,” Paananen told the website of Finnish daily newspaper Helsingin Sanomat, adding that last year the company abandoned four potential new games after testing.

“It is extremely difficult to come up with new games,” he said, citing tough competition in the mobile game market.

Supercell has managed so far to avoid the fate of San Francisco-based Zynga and Finnish rival Rovio, which have both struggled to extend their franchises beyond initial hugely popular game titles.

The company’s video titles are free to download and generate revenue primarily from the fraction of users willing to make small in-game purchases to help them to advance to higher stages of the game.

Its war simulation game Clash of Clans, launched in 2012, is the top grossing app in the Apple iTunes store despite Rovio and Walt Disney having released similar games last year.

Founded in 2010, Supercell introduced its first games for mobile phones in 2011 and sold 51 percent of the business to Japanese technology and telecoms company SoftBank in 2013 for about $1.5 billion.

(Reporting by Jussi Rosendahl; Additional reporting by Eric Auchard; Editing by David Goodman)