Posting on the official @angrybirds Twitter feed, the firm said: "10 million Angry Birds Space downloads in less than 3 days! Thanks to our fans, stay tuned for more!"
The Finnish mobile gaming giant did not indicate what proportion of the downloads was for the free game, and what proportion was the paid-for version.
But past Angry Birds games have tracked at around 25% paid downloads (advert-free), suggesting that Angry Birds Space is already hugely profitable for Rovio.
Angry Birds Space was launched on March 22 on Apple iOS and Google Android devices, as well as PC and Mac.
Rovio initially ruled out a release of the game on handsets running Microsoft's Windows Phone operating system, largely down to the cost of writing a version for the platform.
However, Rovio has now backtracked on that and confirmed that the game will be made available on Windows Phone devices after all.
Rovio chief executive Mikael Hed told Reuters: "We are working closely together with Nokia to bring our games to their platforms. Our mutual goal is to bring the best possible experience to our fans, including all fans using Windows Phone devices."
Angry Birds Space is part of a major expansion of the hugely popular mobile franchise, with Rovio planning four more new games in 2012. More details are expected to follow shortly.
Rovio boss Peter Vesterbacka said in an interview that Angry Birds is soon expected to hit one billion downloads since it launched in 2009. The company has also expanded the franchise into merchandising, animation and even theme parks.
The original Angry Birds has generated more than 700 million downloads across all platforms where it is available. The game was downloaded 6.5m times on Christmas Day 2011 alone.
Watch below the announcement of Angry Birds Space form the International Space Station: