Released initially as Angry Birds Halloween in October 2010, Angry Birds Seasons was not just a cash grab or a simple level pack. It was an ambitious experiment in "live service" gaming before the term was widely used. By tethering its content updates to the calendar year, Rovio Entertainment created a game that evolved alongside the real world, offering players a reason to return every few months for a celebration.
During December, players were often restricted to one new level per day, creating a sense of anticipation and daily ritual. Impact and Legacy Angry Birds Seasons
then 'Add to home screen'
then 'Add to home screen'