Here is the full list of all 25 Skycadia achievements.
The base game contains 16 achievements, and there is 1 DLC pack containing 9 achievements.
Shoot down the bounty Anton
Shoot down the bounty Queen Bee
Shoot down the bounty Mageetle
Shoot down the bounty Hopper
Shoot down the bounty Ladybug
Shoot down the bounty Quito
Shoot down the bounty Aether
Shoot down the bounty Tyrantula
Beat Story Mode