Here is the full list of all 76 Iron Marines achievements. It takes around 25-30 hours to unlock all of the achievements on Windows.
Complete all Campaign Missions in Impossible difficulty.
Defeat Nexus, the Raad Vanguard Master, in Impossible difficulty.
Destroy 30 Raad Portals before any enemy can enter our galaxy through any of them.
Recruit a total of 41 fighters in the Ga’r Warhalls.
Find the 4 mischievous kids lost in the snow on stage 19.
Have the worm throw 5 Holy Hand grenades at the enemies' faces.
Help Sandro unlocks his cowabungous inner self.
Complete Spec Op Laser Tag with the prototype Dropgun unharmed.
Search for the ultimate answer buying 42 different upgrades.
Kill 50 Alpha Fenrirs during a single try of stage 18.
Win Spec Op 'The Last of Them' in less than 7 minutes.
Help the squad of funny penguins achieve maximum coolness on stage 15.
Defeat Mr: Rob070 in Impossible difficulty.
Defeat Mr: Rob070 in Normal or Veteran difficulty.
Defeat 50 tentacles in Mission 13.
Kill 20 or more enemies in less than 3 secs.
Deploy 77 Empyrean squads onto the battlefield.
Defeat the Fell Tyrant in Normal or Veteran difficulty.
Defeat the Fell Tyrant in Impossible difficulty.
Destroy the Fell Bishop's cocoon in less than 4 minutes.
Build a total of 149 Towers.
Beat the Spec Op 'The Colour out of Space' having destroyed all Bishop cocoons in the process.
Destroy a total of 72 Ice Blocks.
Find the 6 Immensity Stones to awake the awesome Mitten of Tranos.
Have 3 Heroes reach maximum level.
Defeat Nexus, the Raad Vanguard Master, in Normal or Veteran difficulty.
Spend 10000 Credits at the Arsenal.
Help the Doctor travel through the timey wimey stuff in Mission 11.
Help the broken Protocol Droid on Mission 10.
Teleport all colonists to safety in Spec Op Darkest Hour.
Save all base colonists in MIssion 5.
Help the space monkeys get the secrets of the Monolith in Mission 4.
Have at least 4 Brawlers active at the same time in Mission 8.
Complete Mission 7 without losing any Squads.
Complete Mission 4 only deploying Mechas.
Help the frozen, weird-looking alien squirrel get his preferred food on stage 18.
Deploy any Hero to battle 100 times.
Destroy a total of 46 Raad Carriers.
Have 100 of your Squads die. They will be missed.
Target to shoot 9 alien jellyfish until they explode.
Complete a Mission with at least one Brawler, one Shellstorm and one Firewalker at the same time.
Kill a total of 150 Jackbots resurrected by Oculus.
Kill 7000 enemies.
Kill a Spammer before it spawns any Inductors.
Free the cute alien from The Claw's grasp in MIssion 12.
Complete the Spec Op In Brightest Day with both Power Cores active.
Earn a total of 5000 Credits.
Have a Hero reach max level.
Defeat the Fell Bishop in the Spec Op A New Despair in less than 30 seconds.
Capture all 3 Core Processor's switches without ever losing any of them in Mission 11.
Rain down a total of 100 Dropguns to the battlefield.
Spend more than 1987 Etherwatts in a single Mission.
Extract 10000 Etherwatts.
Make the Compactors kill 50 Peripheroids.
Kill 343 Peripheroids.
Earn more than 5000 Techpoints.
Complete Mission 9 without losing a single Squad, like a miniature giant space hamster could do.
Destroy the same Assembly Center 3 times.
Kill 4000 enemies.
Beat Spec Op Into Darkness with all survivors.
Have 4 Ranger Squads fighting at the same time in a single Mission.
Attack 1000 times with Rocket Towers.
Kill a total of 300 enemies in Emergency Frequency Spec Op.
Teleport the five missing Captains scattered in Sagan-1.
Save the Ambassadress, save the world!
Kill 17 Etherleeches before they drain your Etherwatts storage.
Wake 21 Grimcrushers from their stone slumber.
Destroy 11 Fell Refineries.
Destroy 8 Worm Cannons in a single Mission.
Extract 1000 Etherwatts.
Kill 500 enemies.
Rescue all 4 wounded soldiers in Mission 3.
Buy any Upgrade from our wonderful selection.
Complete Mission 2 with the COMSAT taking no damage at all.
Complete Mission 1. We knew you could do it.
Click their portrait repeatedly to annoy a Hero during a Mission. They like it!