Facebook's most popular games continue to lose users

[Every other week, Gamasutra examines 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.] When we last looked at the most popular games on Facebook earlier this month, all of Zynga's titles seemed to be taking a hit to their monthly user counts, and that course doesn't appear to have reversed in the last two weeks. The company still controls seven of the stops in the top ten leaderboard for Facebook's games, but all of those titles have shed a significant amount of players, like CityVille, which dropped from 39.5 million users to 36.1 million. Zynga's Texas HoldEm Poker had 36 million users two weeks ago, but now it's at 34.9 million. And the Draw Something app, which interfaces with the mobile games, went from 33.7 million monthly players to 29.5 million.  Audiences also shrank significantly for FarmVille (23.9 million to 22.2 million), CastleVille (23.5 million 21.8 million), and Hidden Chronicles (23.2 million to 21.3 million), which are the fourth, fifth, and six most popular Facebook games respectively. The first non-Zynga title to pop up on the leaderboard, King.com's Bubble Witch Saga at #7, jumped up a spot to #7, but it did lose a few hundred thousand users, as it went from 21.4 million players to 21.1 million. Rovio's Angry Birds fell by two spots to #8 (23.2 million to 20.9 million), and was followed by Wooga's Diamond Dash (19.1 million to 18.9 million) and Zynga's Words With Friends (18.3 million to 17.4 million). You can see the full list of the top 20 Facebook games along with exact monthly active user counts below: All charts and data are courtesy of Facebook application metrics and trends site AppData.