Here is the full list of all 24 Grayland achievements.
Keep on trying!
Are all chicken harmful?
Destroy 10 drones
Destroy 25 drones
Destroy 50 drones
See the rabbit and die.
No rats allowed.
Trainhopper
Plumbird
Sing to the mill.
Get the tutorial completed
You're the Hero!
Kill the Sentinel
Unstoppable
Survive the bees!
Try to stop the train
Collect all the orbs around the Alien.
Get the hidden corn moved
Get shocked!
Try to get in the car
Pickup 250 dots
Smarter than a kid
Smarter than a cat
Kill the Mech!