Selling drugs and killing thugs must be in style this week. Mafia Wars 2 isn't just the fastest growing game on Facebook this week, but the fastest growing app, meaning its 3.8 million new players beat all general apps on the platform, All Facebook reports. The sequel to one of Zynga's most popular game can likely chalk its success up to its recent deluge of cross-game promotions.

Well, that and the fact that the game's team of developers won't stop updating the dang thing. A new update was pushed to the game yesterday, which is rather minor. However, a number of new items have been added: New weapons are in the Boneyard Shop, some fresh ground, water, and air vehicles hit the Global Marketplace along with a few more Halloween items.

Probably the biggest change to the game sounds like the least significant. The Arena leaderboard will now reset monthly, rather than weekly. This gives players a lot more time to excel in the Arena maps and an even better chance at coming out on top. But for the top spot holders, it'll become even more challenging to remain king of the hill.

Zynga recently introduced the Armory to the game, which will be required for the upcoming 5-on-5 battles. This news in growth brings Mafia Wars 2 to 13.7 million monthly players, which for being out for nearly a month is rather slow when it comes to Zynga's games. The original game reached more than 25 million players, so MW2 has a ways to go.