Source: The Developer Website. Angry Birds Seasons is now available for download for iOS and Android devices! Initially launched in the App Store as Angry Birds Halloween, the game has been expanded with a brand new festive level pack Season’s Greedings. Season’s Greedings consists of 25 daily surprises for fans of Angry Birds to enjoy while counting down the days until Christmas. Included in the game is also the 45-level Halloween special edition, now packaged as a separate episode called Trick Or Treat.