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