Here is the full list of all 23 Iron Brigade achievements.
Defeat the Guardian of the Southern Terminal.
Collect 10,000 Scrap.
Defeat the Northern Pylon.
Purchase an item in the store.
Complete the tutorial mission.
Defeat Vlad.
Earn a Bronze Medal on every mission.
Earn a Silver Medal on every mission.
Earn a Gold Medal on every mission.
Earn $20,000 from mission completion rewards.
Complete a mission with 4 players.
Complete 10 Missions with 2 or more players.
Defeat the Northern Pylon with 2 or more players.
Defeat the Guardian of the Southern Terminal with 2 or more players.
Defeat Vlad with 2 or more players.
Defeat 3500 Monovisions.
Kill an enemy with a ricochet sniper shot after 4 bounces.
Destroy 5 Enemies with a single explosion.
Complete a solo mission without firing a shot.
Complete a mission while wearing the uniform of an elite PSI agent.
Defeat the Martian Bear.
Complete wave 20 on Survival: Swamp.
Complete wave 30 on Survival: Settlement.