Top 20 fastest growing Facebook games of the week: 'PetVille', 'Zoo World', 'Happy Pets'

(All rights reserved - Challenge Games / Child's Play)

The top five fastest-growing Facebook games remains more or less the same as last week, with PetVille retaining top spot, and both Happy Pets and FarmVille steady in third and fourth respectively. Further down the chart, there are some new faces jostling for position.

Zoo World climbs to second place, gaining 29.6% more players this week than last, and Fish Isle scrambles from sixth up to fifth as just over 850,000 more players checked up on their aquatic pets. FishVille, last week's number two, appears to have hit a glass ceiling with data suggesting that somewhat surprisingly just over 30,000 additional fish aficionados have checked in the past seven days. New fish, plants, and similar updates appear to be scarce as the game's public profile hasn't announced any new items since December 11.

Further down the chart, School of Wizardry continues to attract with its Harry Potter-esque magical boarding school routine. (Lil) Farm Life has stirred some interest with some limited availability seasonal treats and the implementation of in-game storage.

Ponzi, Inc. is exactly what you'd expect - a fun business game that's going to have to work hard to retain its new players before they tire of it and head off for pastures new. For a game with such a devious title, it's not without a heart - like Gift of the Yeti released earlier in December, Ponzi, Inc.'s donating to children's charity Child's Play in response to pre-determined player actions.

Poker Rivals continues to amass a fanbase at a decent rate but, while just short of 1 million users, has some way to go to catch the kingpin, Texas HoldEm, at seventh place with near 21 million regular players, up 692,005 from last week.

The Facebook games with the biggest weekly increases in monthly active users on December 18 at 15:00 GMT are:

1. PetVille (12,375,721 = +4,486,117 / 36.3%)
2. Zoo World (7,224,649 = +1,849,393 / 25.6%)
3. Happy Pets (11,122,048 = +1,799,416 / 16.2%)
4. FarmVille (72,985,623 = +970,586 / 1.3%)
5. Fish Isle (4,429,201 = +851,987 / 19.2%)

6. Country Life (4,811,496 = +775,749 / 16.1%)
7. Texas HoldEm Poker (20,763,139 = +692,005 / 3.3%)
8. Treasure Madness (3,400,138 = +468,362 / 13.8%)
9. School of Wizardry (2,474,979 = +403,111 / 16.3%)
10. (Lil) Farm Life (6,707,402 = +394,841 / 5.9%)

11. Ponzi, Inc. (763,091 = +332,376 / 43.7%)
12. Poker Rivals (934,232 = +252,324 / 27.0%)
13. Medical Mayhem (1,805,999 = +250,305 / 13.9%)
14. Top Fish (605,081 = +234,524 / 38.8%)
15. Happy Farm (3,118,030 = +232,608 / 7.5%)

16. ???? (198,319 = +194,895 / 98.3%)
17. Super Farkle (1,042,864 = +194,517 / 18.7%)
18. Bubble Popp (408,173 = +189,824 / 46.5%)
19. MindJolt Games (14,150,021 = +180,297 / 1.3%)
20. Crazy Planets (2,780,565 = +174,941 / 6.3%)

Numbers in brackets relate to total monthly users, the increase in monthly users, and the weekly percentage growth.
source: appdata.com