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