Temple Run 2 has amassed over 20 million downloads in its first four days on the iOS App Store, with six million of those coming on day one alone. And though it's initially a free download, the highly-anticipated game has also rocketed to become one of the highest grossing apps in the store thanks to premium in-app purchases. From any angle, those numbers mean Temple Run 2 has enjoyed one of the most successful launches in iOS history. For context, Rovio's Angry Birds Space managed 10 million downloads in three days across various platforms. In terms of non-game apps, the high-profile return of Google Maps to iOS was accompanied by 10 million downloads in 48 hours. The original Temple Run has thus far managed 170 million downloads across iOS, Google Play, and Amazon's Appstore.

Assuming Temple Run 2 can hold its position near the top of the "Highest Grossing" rankings, developer Imangi Studios will have proven yet again that the free-to-play pricing model can find success — though that success doesn't translate to all games. With Temple Run 2 slated to arrive on Android this week, the question naturally becomes whether users of Google's platform will embrace the title to the same extent as iOS gamers, or perhaps even best these impressive App Store figures.