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.
Defeat Mr: Rob070 in Impossible difficulty.
Defeat Mr: Rob070 in Normal or Veteran difficulty.
Destroy the Fell Bishop's cocoon in less than 4 minutes.
Win Spec Op 'The Last of Them' in less than 7 minutes.
Defeat the Fell Tyrant in Impossible difficulty.
Defeat the Fell Tyrant in Normal or Veteran difficulty.
Have at least 4 Brawlers active at the same time in Mission 8.
Deploy any Hero to battle 100 times.
Have 100 of your Squads die. They will be missed.
Deploy 77 Empyrean squads onto the battlefield.
Make the Compactors kill 50 Peripheroids.
Kill a total of 150 Jackbots resurrected by Oculus.
Complete Spec Op Laser Tag with the prototype Dropgun unharmed.
Find the 6 Immensity Stones to awake the awesome Mitten of Tranos.
Recruit a total of 41 fighters in the Ga’r Warhalls.
Complete Mission 4 only deploying Mechas.
Save all base colonists in MIssion 5.
Complete Mission 7 without losing any Squads.
Defeat 50 tentacles in Mission 13.
Have 4 Ranger Squads fighting at the same time in a single Mission.
Build a total of 149 Towers.
Have 3 Heroes reach maximum level.
Help the broken Protocol Droid on Mission 10.
Help the squad of funny penguins achieve maximum coolness on stage 15.
Complete the Spec Op In Brightest Day with both Power Cores active.
Rain down a total of 100 Dropguns to the battlefield.
Beat the Spec Op 'The Colour out of Space' having destroyed all Bishop cocoons in the process.
Destroy 30 Raad Portals before any enemy can enter our galaxy through any of them.
Search for the ultimate answer buying 42 different upgrades.
Destroy a total of 72 Ice Blocks.
Defeat Nexus, the Raad Vanguard Master, in Normal or Veteran difficulty.
Find the 4 mischievous kids lost in the snow on stage 19.
Kill 50 Alpha Fenrirs during a single try of stage 18.
Help the frozen, weird-looking alien squirrel get his preferred food on stage 18.
Destroy a total of 46 Raad Carriers.
Complete a Mission with at least one Brawler, one Shellstorm and one Firewalker at the same time.
Kill 7000 enemies.
Help Sandro unlocks his cowabungous inner self.
Kill a Spammer before it spawns any Inductors.
Free the cute alien from The Claw's grasp in MIssion 12.
Earn a total of 5000 Credits.
Have a Hero reach max level.
Capture all 3 Core Processor's switches without ever losing any of them in Mission 11.
Help the Doctor travel through the timey wimey stuff in Mission 11.
Destroy the same Assembly Center 3 times.
Kill 343 Peripheroids.
Extract 10000 Etherwatts.
Complete Mission 9 without losing a single Squad, like a miniature giant space hamster could do.
Defeat the Fell Bishop in the Spec Op A New Despair in less than 30 seconds.
Earn more than 5000 Techpoints.
Target to shoot 9 alien jellyfish until they explode.
Teleport all colonists to safety in Spec Op Darkest Hour.
Kill 4000 enemies.
Spend 10000 Credits at the Arsenal.
Beat Spec Op Into Darkness with all survivors.
Attack 1000 times with Rocket Towers.
Teleport the five missing Captains scattered in Sagan-1.
Kill 20 or more enemies in less than 3 secs.
Kill a total of 300 enemies in Emergency Frequency Spec Op.
Save the Ambassadress, save the world!
Wake 21 Grimcrushers from their stone slumber.
Kill 17 Etherleeches before they drain your Etherwatts storage.
Destroy 11 Fell Refineries.
Spend more than 1987 Etherwatts in a single Mission.
Destroy 8 Worm Cannons in a single Mission.
Help the space monkeys get the secrets of the Monolith in Mission 4.
Buy any Upgrade from our wonderful selection.
Have the worm throw 5 Holy Hand grenades at the enemies' faces.
Kill 500 enemies.
Extract 1000 Etherwatts.
Rescue all 4 wounded soldiers in Mission 3.
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!