Angry Birds creator Rovio Entertainment announced Chief Executive Mikael Hed will step down from that role at the beginning of next year, a move that comes several months after the entertainment company reported muted 2013 results.

Hed will be succeeded by Pekka Rantala, who joined Rovio in June to serve as chief commercial officer and will take the CEO reins on January 1. Hed has been nominated to serve on Finnish-bsaed Rovio’s board and will also serve as chairman of Rovio Animation Studios, where he will oversee animation and movies.

Angry Birds, which originally launched as a mobile game in 2009, has become a powerful force in the licensing and entertainment world. Hed led the company throughout its rapid growth in its early years. He also steered the company to move into other pockets of entertainment beyond mobile gaming. A number of physical toys designed by American-based toy manufacturer Hasbro HAS hit retail shelves last year, and a full-length animated Angry Birds movie is also planned.

But The Wall Street Journal and other media outlets have noted the company has struggled in recent years among increased competition from other mobile game developers, including Candy Crush creator King Digital Entertainment KING and Finland-based Supercell, which both currently have a few titles among the top grossing iPhone apps. Meanwhile, Rovio’s full-year revenue grew by less than 4 million euros to 156 million euros ($206 million) in 2013 from the prior year. Net profit after tax slid in 2013 after sharply rising the prior two years, as Rovio invested in animation and video distribution and other aspects of the business.