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