In a 2023 leak of unreleased content from different iOS games, an app titled Angry Birds Island - or alternatively Angry Birds Hatchery - was discovered. The prototype was simply a version of the original Angry Birds with two major differences
• A mode called "Hatchery", which shows an overworld map of an island with a row at the bottom of toys and furniture
• The first two worlds of the original game, but with an option to select from a set of birds, all of which appear to be hybrids of the regular birds
This seemingly implies some kind of pet simulator mode with an egg breeding mechanic, not unlike the Chao Gardens from the Sonic Adventure series. It is unknown if this was planned as an update for Angry Birds or a new spin-off.

Level 8-3 was designed by a 5-year old fan named Ethan, whose mother sent Rovio his concept art for an Angry Birds stage through an email.

In 2019, Rovio Entertainment pulled the game, alongside several other installments, from digital store shelves without announcement. This drew heavy criticism from fans. Rovio eventually apologized to fans and rereleased the game as a “Rovio Classic” nearly three years later, which was recreated using the Unity engine. The version rereleased resembles the 2012 version.

A study by the Ryerson University in Toronto showed that playing Angry Birds made players consume 50 fewer calories at mealtime than at a meal having not played it prior. The reason was that people felt happier after playing the game, which made them consume less.

It has been confirmed that the Pigs in the game have no desire to harm the birds.

During development, Rovio got the idea to make the enemies pigs because of the 2009 swine flu epidemic. The pig's sickly green color is a reference to this.

As of 2011, more than 200,000 collective years were spent playing Angry Birds, roughly the same amount of time that modern humans have existed.