Here is the full list of all 13 Skyling: Garden Defense achievements worth 1,000 gamerscore.
Completed 5 levels
All levels are now unlocked!
You learned the story of the Skyling gardens!
Complete 10 levels to unlock
Complete 15 garden levels to unlock
Complete 20 Levels to unlock
Complete 25 levels to unlock
Complete 30 levels to unlock
Kill 50 monsters to unlock
Kill 3 monsters at once to unlock
Finish 50 levels to unlock (including replays)
Earned by bringing a cat to the exit 25 times
Use a slug to take out three other monsters