Angry Birds Rio hasn't seen an update in awhile but that apparently doesn't mean the game is dead, especially since there is a sequel to the movie coming out. Rovio has pushed a new update to the game that brings a bunch of new levels as well as something Rovio hasn't really done before with an older title of their - refreshed the graphics.
This update brings an additional 20 new levels to the with another 6 bonus levels to unlock. Pretty standard for the most part when it comes to the amount of content that an Angry Birds game gets with an update.
Something that isn't standard though is Rovio refreshing the graphics to one of their older titles, something they haven't really done before but they did do it with this one. According to the changelog, Rovio decided to do this in preparation for Rio Chapter 2. Dolphins are also present and need to be rescued, not just birds anymore. To do that, you'll need to use the new move in the game to dive underwater.
If you still have Angry Birds Rio installed on your Android device, you can download the update at anytime since it is now live on Google Play.