Here is the full list of all 23 Iron Danger achievements.
You successfully completed Iron Danger. Congratulations!
You found the fifth Shard. Your enemies tremble before you.
You put the Tyrannogrouse out of its misery.
Collect 30 mushrooms.
Eat roosterfish roasted over campfire.
You found the fourth Shard, and it eases your pain.
Defeat 100 enemies.
You found the third Shard, and it makes you shiver.
Grow stealth grass 20 times.
You found the second Shard and feel the nature's call.
Kill 30 keyus.
Die 100 times.
Use Earthquake while boosted by fire.
You found the fabled Healer of Brumehead.
You found the first Shard poking through your chest.
Collect 20 berries.
You healed the wounded Tyrannogrouse.
Blow yourself up by shooting explosive arrow while on fire.
Kill the alpha Roosterfish in the temple under Rimfeden.
Take a troll into the Northlander camp.
Find and read the recipe in Kalevala.
Hunt down and slay all of the trolls in Bleakshore.
Destroy all three gates leading into the Northlander camp.