Here is the full list of all 31 HammerHelm achievements.
Meet Grrrumble and learn his story
Place a sewer entrance
Place a water well
Spend 5 skill points
Have a Stomemason craft a fireplace
Place a stone entrance
Craft a full set of gold armor
Place 10 houses
Place a weaponsmith and an armorsmith
Craft a full set of jade armor
Place a fishing pier and assign a fisherman
Craft a healing potion
Place a brewery and assign a brewer
Have a carpenter and 3 fully furnished homes
Craft a full set of iron armor
Destroy 4 monster camps
Craft a shield
Craft a full set of copper armor
Clear monsters from a cave
Place a farm and assign a farmer
Meet Shaydee the Goblin
Destroy monsters in a dungeon
Craft any weapon
Mine three ore rocks
Chop down a tree
Place a house
Place 4 stone towers
Craft a full set of diamond armor
Craft a full set of blood stone armor
Imbue a weapon using a gem
Destroy a necromancer