Full list of all 20 Angry Birds Seasons achievements worth 200 gamerscore. It takes around 10-12 hours to unlock all of the achievements on Windows Phone.
Smash 300 pigs
Finish Trick or Treat
Smash 300 pumpkins
Finish all Season's Greedings levels
Smash 1000 presents
Finish Hogs and Kisses
Break 300 chocolate boxes
Finish Go Green, Get Lucky
Break 300 pots of gold
Finish Easter Eggs
Pop 300 Piggy Bunnies
Finish all Summer Pignic' levels
Pick 300 flowers
Finish Moon Festival
Break 300 lanterns
Finish Ham'o'ween
Break 300 skeletons
Unlock Orange Bird
Finish Wreck the Halls
Break 300 Cookies