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