In the past year, Candy Crush Saga has been downloaded some 500 million times and played more than 150 billion times. The game got off to a slow start as an online game two years ago, but after some design changes expressly intended to thwart players tempted to put it down, it has become a global phenomenon--popular everywhere from Brazil to Hong Kong. It is the first game of the smartphone era to top the most-downloaded charts for Apple iOS, Google Android and Facebook simultaneously.
The rules of play are simple: line up three candies of the same color and repeat. But within that basic premise, Candy Crush's maker, a London-based software company called King, has devised an apparatus that is almost frighteningly effective at turning new players into fanatics--and making money too. Which is a particularly sweet trick considering that Candy Crush is free to download and free to play.