Here is the full list of all 15 Double Trouble achievements.
Fly 10 airplanes
Fly an airplane
Deliver 10 animals
Visit 10 observation posts
Collect 100 pieces of fruit
Collect 10 pieces of fruit
Build up 10 town tiles
Deliver your first animal to a farm
Collect 1000 pieces of fruit
Deliver 100 animals
Delivered a unicorn
Build up 100 town tiles
Build up 1000 town tiles
Launch a rocket
Launch 10 rockets