The physics puzzle game is the 800-pound gorilla of the App Store. Whether in its , , or , Angry Birds dominates the sales charts of Apple's mobile app outlet. You can buy Angry Birds plush toys. A may be in the works. For all I know, Steve Jobs is going to invite one of the birds--the chubby, particularly irritated-looking red one, I'd guess--to join Apple's board of directors.

For now, though, Angry Birds and developer are content to lend their considerable rub to promote someone else's movie. In conjunction with next month's release of the animated motion picture , Rovio has rolled out a new version of its popular game-- for the iPhone and iPod touch and for the iPad.

The movie tie-in necessitates some changes to the usual Angry Birds storyline, in which the foul-attitude fowls do battle with an army of snickering green pigs. Instead of using your battalion of birds to crush the pigs and their assorted fortifications, you're on a mission of mercy in Angry Birds Rio--you're smashing through cages to free the exotic bird heroes that star in .

Otherwise, gameplay in Angry Birds Rio will be familiar to anyone who's played any other game in the franchise. Your birds have different powers--some explode, some feature speed bursts, some split into three, and so on--which can come in handy when solving Angry Birds Rio's various puzzles. The cages confining your feathered friends are surrounded by various structures made out of wood, glass, and metal--some of which are easier to break through than others. You rack up points for freeing the birds while reducing those structures to rubble. Each stage you successfully clear earns a rating of one to three stars depending on how much damage you're able to inflict and how many birds it takes to do it.

As I write this, Angry Birds Rio features two episodes, containing a total of 60 levels. Four more episodes are planned throughout 2011 via updates to the app.