Here is the full list of all 84 Ostrich Island achievements.
You found the Santa's Hat.
You unlocked Score Collector ability.
You lowered a bridge without hitting it.
You found Statuette of Bathilda, sister of Ostrich.
You found Statuette of Egbert, brother of Ostrich.
You installed Water Control Device.
You joined Workshop, created a skin and gifted it to Ostrich Island Community.
You found the skin: Cheetah
You found the Strange Hat.
You unraveled the destiny of Giant Egg.
You reached 50% mark on the way to the game mastery.
You found the skin: Striped
You found Statuette of Dedrik, grandpa of Ostrich.
You have finished the game.
You walked on a beach with at least 3 chicks.
You found the skin: Bamboo
You found a hidden bonus on the first island.
You increased Eggs Converter Speed.
You found the Bowler Hat
You discovered The City Of Lost Chickens!
You unlocked Heavy Hitter ability.
You found the location of Labyrinth.
You scored a goal while playing with mangos!
You solved the tree puzzle on the first island.
You found the Photo Camera.
You caught all the fish on the second island.
You caught 7 butterflies.
You found the Cork Hat
You increased Eggs Converter efficiency.
You found the skin: Chicken
You found the Elegant Hat.
You found the skin: Zebra
You found Statuette of Manfred, nephew of Ostrich.
You found the Cowboy Hat!
You found Statuette of Agmund, cousin of Ostrich.
You found the skin: Black & White
You do like to play dirty, don't you?
You found Statuette of Osrik, uncle of Ostrich.
You activated all portals on Island 4.
You found the Sunglasses.
You unlocked Jumper ability.
You activated Eggs Converter.
You found the skin: Tiger
You found the Hat of Sea Dog.
You found the Treasure Island.
You found the Green Hat.
You found the skin: Lizard
You found the skin: Domino
You collected the third Egg in a split second.
You found Statuette of Alarice, aunt of Ostrich.
You found the White Hat.
You unlocked Sharp Vision ability.
You unlocked Fast Walker ability.
You have collected all eggs on some island.
You found Statuette of Dagna, niece of Ostrich.
You unlocked Egg Master skill.
You collected two eggs in the blink of an eye.
You mastered Co-op mode and finished with higher score several times.
You completed the first island.
You collected all available bonuses on Tiny Island.
You destroyed an idol without using a super power.
You fixed the broken portal before having fun.
You haven't seen such an Egg before.
You found a fish in a mud!
You destroyed over 50 trees on some island!
You found all the hidden food on island six.
You survived on the cloud #11 for 5 minutes.
You found Statuette of Morgen, father of Ostrich.
You found Statuette of Alda, mother of Ostrich.
You found a beautiful doll.
You found the Peaked Cap.
It's Halloween Time!
You found the Heart-Shaped Glasses.
You found the skin: Cow
You took 50 photos.
You are the King!
You unlocked Sprinter skill.
You unlocked Brawler skill.
You finished the Game+ mode.
You completed the collection of beautiful Ostrich Island photos.
You have discovered every nook and cranny of Ostrich Island. You are the Master of this game.
You destroyed a small army of bony fiends by dropping a tree on it.
You sent home two chickens at once.
You have scored a goal with a lobster. Birds gonna get angry.