As part of this week’s earnings call, Zynga revealed its excitement surrounding the launch of FarmVille 2: Country Escape on iOS and Android. Launched on April 17, the game has already been downloaded more than four million times, with this early success also boosting the player base for FarmVille 2 on Facebook.

FarmVille 2: Country Escape is a completely new farming experience, only available on mobile, but it connects back to the FarmVille 2 web game through a two-way exchange system. Players can send items from their web farm to the mobile game, and vice versa, allowing gamers to collect valuable resources that may help them make progress in one or both games.

Thanks to this connection, Zynga COO Clive Downie says the company is “seeing encouraging indicators around engagement, retention, organic power and connectedness with the FarmVille 2 web game.”

According to our app tracking service AppData, FarmVille 2 on Facebook is the top growing app based on monthly active users (MAU), having gained over 3.3 million MAUえーゆー in the past week. The game currently sits at 21.5 million MAUえーゆー, and is the No. 5 game on the platform (the No. 13 app overall).

At launch, FarmVille 2: Country Escape was featured as an Editor’s Choice on the Apple App Store, and as a ‘Top Tier’ product on Google Play. In the US, the game has achieved the No. 1 spot for top free app and top free game on iPad, as well as breaking into the top 20 for top grossing apps on both iPad and iPhone.

More information on FarmVille 2: Country Escape can be found in our coverage on Inside Mobile Apps.