Here is the full list of all 21 Narco Terror achievements.
Upgrade a weapon
Complete Mission 01
Kill 20 enemies with grenades
Kill 6 enemies with a single grenade
Kill 150 enemies
Destroy 50 vehicles
Upgrade all weapons
Find 5 collectables
Find all the collectables
Complete the game on any difficulty
Complete the game on hardcore difficulty
Get to South America
Play Co-Op mode for 5 minutes
Melee kill 10 enemies
Kill 3,000 enemies in total
Destroy 5 ground enemies with your aircraft
Complete a vehicle minigame without getting hit
Complete any mission without dying
Meet Delgado for the first time
Earn 15,000 dollars
Use all special ammo and weapons