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