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