Here is the full list of all 15 Click Defense achievements.
Survive the first night.
Survive the second night.
Survive the third night.
Survive the fourth night.
Survive the fifth night.
Survive the sixth night.
Survive the seventh night.
Survive the eighth night.
Survive the ninth night.
Survive the tenth night.
Survive the second night without any tech upgrades.
Survive the fourth night without any tech upgrades.
Survive the sixth night without any tech upgrades.
Survive the eighth night without any tech upgrades.
Survive the tenth night without any tech upgrades.