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