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