Rovio, the developer behind the smash hit Angry Birds, is about to release a new iteration of its game ‘Angry Birds Seasons’. This time around, the theme will be St. Patrick’s Day. Not much is known about the update just yet, but the game is expected to look radically different, with green-themed levels, and plenty of festive pigs to slaughter. Angry Birds St.Patrick’s Day Edition will come as a free update to the Angry Birds season app, which already features Halloween, Christmas and Valentine’s Day themed levels. The update should bring about fifteen new levels, and a slew of new achievements. Thanks to this new update, Angry Birds Seasons will offer a total of 100 levels. As usual, Rovio is doing an excellent job at keeping its apps ‘fresh’, as the developer does not charge existing users for the additional levels, which in turn helps create some buzz around the game, and convince iOS-powered device users who do not own the game to try it out. Angry Birds Seasons for iPhone is available on the App Store for $0.99, while Angry Birds Seasons HD for iPad is available for $1.99.