Rovio announced today that its Angry Birds games have been downloaded more than one billion times, an astounding accomplishment for a simple slingshot game with a goofy birds-vs-pigs backstory.

"THANK YOU to all of our incredible fans! This is only the beginning of our story, keep your eyes peeled for what’s coming up next from Rovio!," the company wrote in a brief blog post.

It's been only six months since Rovio reported that Angry Birds had topped 500 million downloads. Since then, the developer has released Angry Birds Space, which reached 50 million downloads a mere 35 days after its debut.

Angry Birds fans play 300 million minutes of the game every day, Rovio said in November 2011.

So what's next? Rovio is planning a feature film that will dig deeper into the characters' personal histories. It's also developing Angry Birds-themed amusement parks in China.

You can't fault Rovio for milking a successful franchise for all it's worth, but at what point will the Angry Birds mania end?