Market Mayhem is a brand-new episode with 30 regular levels and 15 hidden strawberries. Players just need to collect all those hidden strawberries to unlock 2 new bonus levels. On the other side, marmoset monkeys are wreaking havoc in the market and your mission is to stop them.
The update includes 36 new levels (between standard and special). The new Angry Birds Rio episode is free and can be downloaded from Google Play.
Source: Angry Birds (Facebook Page)