Zynga Giants Top Fastest-Growing Facebook Games

[Every other week, Gamasutra examines the fastest-growing Facebook games according to monthly active users, looking at which titles and developers are having the most success attracting new players on the social network.] Zynga's biggest titles, which also happen to have the biggest audiences out of any games on Facebook, continue to lead the Top Gainers list, with big names like FarmVille and CityVille growing again after a year of shedding users. Due to a number of factors, including Facebook changing how it counts "active users" for apps several months ago, many of the biggest games on the social network now report much smaller user counts -- some smaller by tens of millions. FarmVille, though, has seen an uptick lately. Two weeks ago it added 600,000 users, and this week it's the fastest-growing game with 1 million new players -- bringing its total to now 33.1 million virtual farmers. CastleVille, the most recently launched game from Zynga, is still growing, though not as rapidly as previous weeks. It picked up 900,000 new users (compared to 7.1 million two weeks ago) for a total of 38.6 million players. CityVille is another title that saw a dramatic drop in 2011, crossing the 100 million user mark earlier this year, and now halved to 49.3 million. The city-building sim done well in the last week, though, gaining 500,000 new players. Four games attracted around 300,000 new users in the last seven days: Zynga's Adventure World (9.8 million total) and Words With Friends (13.8 million), Tetris Online's Tetris Battle (9.2 million), and Wooga's Magic Land (2.7 million). Digital Chocolate's Galaxy Life has 240,000 new players (1.1 million total), while Ninja Saga (4.5 million), RockYou's Zoo World (2.3 million), and Halfquest's Arabic game Happy Farm each welcomed about 200,000 new users. The full list of the top 20 fastest growing Facebook games along with exact monthly active user counts, are as follows: All charts and data are courtesy of Facebook application metrics and trends site AppData.