Angry Birds has become the first game to achieve 500 million downloads.The milestone was reached less than two years after it was released.Growing popularity in China, where it\'s been downloaded 50 million times, and strong figures from elsewhere in the world has ensured its success.\"This is a fantastic landmark achievement for us, and we\'re extremely delighted to see such an incredible amount of people enjoying our games,\" said Mikael Hed, CEO of Rovio.The developer is certainly trying to make the most of the game\'s success.The company has already shipped 10 million Angry Birds toys and its first retail outlet is due to open in Helsinki.More stores will follow in China within 12 months where fake merchandise has caused it some problems.There are also book and film plans in the pipeline and Rovio intends to expand the brand into other areas.Rovio recently raised £26m in investment, which valued the company at £760m.here has also been talk of a stock market flotation next year.The plans mean the company has come a long way since it was on the verge of going bust just two years ago.It was founded in 2003 but by 2009 the company was struggling and down to 12 employees.It now employs 170 people and has publicly stated that its next goal is to reach one billion fans.