King is a very, very rich company. Its flagship mobile game – Candy Crush Saga, a game so omnipresent that it surely can’t have escaped your notice over the past few years – made almost $2bn a year at its height in 2013, and still pulls in hundreds of thousands a day. It is, by any possible measure, one of the world’s most successful video games of any era. Activision-Blizzard spent $5.9 billion on acquiring King in November last year. Even a game that successful does not guarantee the long-term security and success of a company, however. Just ask Angry Birds developer Rovio, or Farmville developer Zynga, both of which have been…