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