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