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.
Recruit a total of 41 fighters in the Ga’r Warhalls.
Win Spec Op 'The Last of Them' in less than 7 minutes.
Deploy any Hero to battle 100 times.
Find the 6 Immensity Stones to awake the awesome Mitten of Tranos.
Beat the Spec Op 'The Colour out of Space' having destroyed all Bishop cocoons in the process.
Search for the ultimate answer buying 42 different upgrades.
Teleport all colonists to safety in Spec Op Darkest Hour.
Beat Spec Op Into Darkness with all survivors.
Complete the Spec Op In Brightest Day with both Power Cores active.
Defeat the Fell Bishop in the Spec Op A New Despair in less than 30 seconds.
Complete Spec Op Laser Tag with the prototype Dropgun unharmed.
Complete all Campaign Missions in Impossible difficulty.
Defeat Nexus, the Raad Vanguard Master, in Impossible difficulty.
Make the Compactors kill 50 Peripheroids.
Help Sandro unlocks his cowabungous inner self.
Destroy the Fell Bishop's cocoon in less than 4 minutes.
Spend 10000 Credits at the Arsenal.
Destroy a total of 72 Ice Blocks.
Deploy 77 Empyrean squads onto the battlefield.
Help the Doctor travel through the timey wimey stuff in Mission 11.
Have 100 of your Squads die. They will be missed.
Defeat Mr: Rob070 in Normal or Veteran difficulty.
Defeat Mr: Rob070 in Impossible difficulty.
Kill a total of 150 Jackbots resurrected by Oculus.
Have 3 Heroes reach maximum level.
Build a total of 149 Towers.
Defeat the Fell Tyrant in Normal or Veteran difficulty.
Defeat the Fell Tyrant in Impossible difficulty.
Have the worm throw 5 Holy Hand grenades at the enemies' faces.
Defeat Nexus, the Raad Vanguard Master, in Normal or Veteran difficulty.
Find the 4 mischievous kids lost in the snow on stage 19.
Destroy 30 Raad Portals before any enemy can enter our galaxy through any of them.
Kill 50 Alpha Fenrirs during a single try of stage 18.
Kill 7000 enemies.
Help the frozen, weird-looking alien squirrel get his preferred food on stage 18.
Destroy a total of 46 Raad Carriers.
Help the squad of funny penguins achieve maximum coolness on stage 15.
Defeat 50 tentacles in Mission 13.
Have a Hero reach max level.
Kill a Spammer before it spawns any Inductors.
Free the cute alien from The Claw's grasp in MIssion 12.
Attack 1000 times with Rocket Towers.
Earn a total of 5000 Credits.
Capture all 3 Core Processor's switches without ever losing any of them in Mission 11.
Extract 10000 Etherwatts.
Rain down a total of 100 Dropguns to the battlefield.
Kill 343 Peripheroids.
Destroy the same Assembly Center 3 times.
Help the broken Protocol Droid on Mission 10.
Complete Mission 9 without losing a single Squad, like a miniature giant space hamster could do.
Kill 4000 enemies.
Kill 20 or more enemies in less than 3 secs.
Kill a total of 300 enemies in Emergency Frequency Spec Op.
Have 4 Ranger Squads fighting at the same time in a single Mission.
Earn more than 5000 Techpoints.
Complete a Mission with at least one Brawler, one Shellstorm and one Firewalker at the same time.
Have at least 4 Brawlers active at the same time in Mission 8.
Spend more than 1987 Etherwatts in a single Mission.
Complete Mission 7 without losing any Squads.
Teleport the five missing Captains scattered in Sagan-1.
Save the Ambassadress, save the world!
Wake 21 Grimcrushers from their stone slumber.
Kill 17 Etherleeches before they drain your Etherwatts storage.
Target to shoot 9 alien jellyfish until they explode.
Save all base colonists in MIssion 5.
Complete Mission 4 only deploying Mechas.
Destroy 8 Worm Cannons in a single Mission.
Destroy 11 Fell Refineries.
Help the space monkeys get the secrets of the Monolith in Mission 4.
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!