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