Complete the indicated task to unlock the corresponding achievement.

Achievement	How to unlock
Backward Compatibility	Shoot 10 birds left of the slingshot and off-screen.
Bird Slinger	Shoot 5,000 birds.
Bull's Eye	Directly hit a pig with a bird from above.
Egg Cracker	Get 10 Golden Egg stars.
Egg Hunter	Find 10 Golden Eggs.
Feather Collector	Earn 100 feathers.
Feather Gatherer	Earn 200 feathers.
Feather Picker	Earn 50 feathers.
Hard as a Rock	Smash all stalactites.
Kepicker	Smash 5,000 ice blocks.
Space Invader	Shoot the Yellow Bird way up high, into space.
Stonecutter	Smash 5,000 stone blocks.
Ultimate Bejeweler	Smash 5,000 jewels and gems.
Wilheim Tell	Hit a flying bird with another bird.
Woodpecker	Smash 5,000 wooden blocks.