Here is the full list of all 29 Alien Kingdom achievements.
Killed at least 100 enemies.
Killed at least 200 enemies.
Killed at least 500 enemies.
Killed at least 1000 enemies.
Killed at least 2500 enemies.
Killed at least 5000 enemies.
Killed at least 10000 enemies.
Slay the World Boss of Aesa at least once.
Slay the World Boss of Belzun at least once.
Slay the 1st World Boss of Corris at least once.
Slay the 2nd World Boss of Corris at least once.
Slay the 1st World Boss of Delkur at least once.
Slay the 2nd World Boss of Delkur at least once.
Through vigorous training you've reached level 2!
Through vigorous training you've reached level 5!
Through vigorous training you've reached level 10!
Through vigorous training you've reached level 15!
Through vigorous training you've reached level 25!
Through vigorous training you've reached level 50!
Through vigorous training you've reached level 100!
You've rescued your first defenseless villager!
You've rescued 5 defenseless villagers!
You've rescued 10 defenseless villagers!
You've rescued 15 defenseless villagers!
You've rescued 25 defenseless villagers!
You've rescued 50 defenseless villagers!
You've rescued 100 defenseless villagers!
You've rescued 250 defenseless villagers!
You've rescued 500 defenseless villagers!