Here is the full list of all 29 Kingdom Defense achievements. It takes around 0-1 hour to unlock all of the achievements on Windows.
Level 11 completed
Level 12 completed
Level 9 completed
Level 10 completed
Level 1 completed
Level 2 completed
Level 3 completed
Level 4 completed
Level 5 completed
Level 6 completed
Level 7 completed
Level 8 completed
Sell tower
Improve hp
Improve accurancy
Improve speed
Set fire shells
Build archers tower
Set trap
Build magician tower
Disable sounds
Russian language
English language
Improve damage
Build knights tower
Use mini knights help
Exit the main menu
Exit the game
Enable sounds