Every other week, we examine the most popular Facebook games (according to monthly active users), looking at the top titles and developers on the social network to see who's attracting or losing players.Almost all of the top 20 games on Facebook continued to lose users in the past two weeks, with Zynga'staking the biggest hit: now down to 66.6 million monthly active users (surely an unlucky number) from its already deflated count of 75.5 million in our last count Since its peak of 85 million users in March, before Facebook enacted changes to its application notification system to curb the "spam" many apps depend on for the viral growth, the farming simulation game has shed more than 18 million users.Zynga's, currently the second most popular game on the social network with 28.3 million players, fared much better as it climbed up a spot and actually brought in some 200,000 new users since late May, but the same can't be said for the studio's other releases.The developer's(#4),(#5),(#6),(#8),(#10), and(#16) each gave up a significant number of gamers, some as little as 300,000 but most closer to's loss of 3.7 million.Electronic Arts/Playfish's social titles --(#9),(#13) and(#15) -- suffered similar troubles, losing 1.5 million users, 1.9 million users, and 3 million users in the past two weeks respectively.The only winner here in recent weeks is Mindjolt Games, a portal for more than a thousand casual online titles, which managed to jump from #14 to #7 with 5.5 new monthly active users for a total of 18.4 million -- but only after losing 13.1 million players in April.All charts and data are courtesy of Facebook application metrics and trends site AppData