Here is the full list of all 35 Insurgency: Sandstorm achievements. It takes around 20-25 hours to unlock all of the achievements on Windows.
Drive a vehicle full of teammates for more than 15 seconds.
Call in fire support ten times as an Observer.
As a Commander, kill an enemy using fire support.
Capture 100 objectives.
Destroy an enemy air support vehicle.
Be the Most Valuable Player of a round.
Destroy an enemy vehicle with a mine.
Win a match of Firefight.
Capture an objective as the last member of the team alive.
Kill three or more enemies with a single grenade or explosive.
Navigate through chemical gas while wearing a gas mask.
Destroy an enemy weapon cache using a remote explosive charge.
Win a match of Checkpoint.
Successfully rig and destroy an enemy weapon cache.
Kill an enemy after blinding them with a flashbang
Kill an enemy while blinded by a flashbang
Kill an enemy with the last bullet of your magazine.
Purchase your first item in the Appearance menu.
Kill an enemy while they are reloading.
Block an objective from being captured and then clear it.
Kill an enemy with a knife.
Kill an enemy by bashing in a door.
Kill an enemy with a vehicle.
Kill an enemy using the mounted weapon on a vehicle.
Kill an enemy driver with the mounted weapon of their vehicle.
Kill an enemy with an enemy's live grenade.
Kill an enemy by burning them.
Kill an enemy while vaulting.
Win a match of Push.
Kill an enemy by shooting through something.
Kill an enemy right after performing a speed reload.
Kill 3 enemies with a headshot in a row.
Get the first kill in a round.
Kill an enemy without using weapon sights.
Complete the tutorial mission.