Here is the full list of all 20 VALA: Vicious Attack Llama Apocalypse achievements worth 1,000 gamerscore.
Cause $100,000,000 of damage to the world
Kill the entire US & Canada llama population
Destroy 200 magazine stands
Clear 10 sections without missing a shot
Unlock every perk
Unlock every weapon
Extinguish 10 llamas that are on fire
Revive a friend
Complete District 3
Complete District 2
Kill ovar 9000 llamas
Make 1000 ice cubes
Destroy 20 phone booths
Complete District 1
Get the framerate down to peasant-level
Wash the camera 5 times
Knock over 50 street-lights
Unlock your first weapon
Clear 2 areas without using a weapon
Kill 30 llamas