Social-game apps on smartphones have become a massive market, and every year another new mega-hit game emerges with players in the multimillions. The games themselves are usually free to play, but staggering profits generated by optional in-game purchases have made the makers of these apps extremely rich, changing the power balance within the game industry.
However, almost no one, even the makers themselves, can tell which game will become the next smash, leaving investors scratching their heads.
"Monster Strike," or "Mon-Suto" as it is known to its fans, is a recent success. It was released last October by mixi, operator of the once-dominant Japanese social-networking service of the same name. The game is similar to digital billiards or bowling, with monsters instead of balls or pins. Players launch their monster by dragging it back and releasing it, like in "Angry Birds" — a game that was itself a global hit, though less popular in Japan — and clear stages by capturing and raising monsters. Friends can link over Bluetooth for team play.