Here is the full list of all 41 Goliath achievements worth 1,000 gamerscore.
Build your first Stone Goliath
Kill 500 enemies
Get 5000 gold
Kill 50 enemies with the revolver
Get Drogkh to the base
Meet the Forest Brotherhood
Complete the tutorial
Build your first Wooden Goliath
Build your first Metal Goliath
Build your first Crystal Goliath
Unlock all unique Goliaths
Visit all shards in the game
Complete 10 side quests
Reach level 20
Reach level 40
Kill 50 enemies with Wooden Goliath catapult
Kill 50 enemies with Stone Goliath ram
Kill 50 enemies with Metal Goliath rockets
Kill 50 enemies with Crystal Goliath lightning storm
Defeat the Cursed Monster
Defeat the Great Treasure Hunter
Defeat the Castle
Defeat the Guard of the Citadel
Defeat the Final Boss
Get Sheriff Willy to the base
Get T1NK3R3R to the base
Get Baroness Victoria to the base
Get Thomas F. Melton to the base
Break 50 Goliaths
Equip Goliath with two fabulous weapons at the same time
Spend 10.000 gold in shops
Get 100% reputation for all three factions
Learn Trollese, Gnarkish and Golemian
Meet the Forgers
Meet the Created
Successfully perform the ceremony of Pygmy's marriage
Find the Citadel
Became a member of Order
Re-educate the gang of youth thugs
Complete all quests in the House of Miracles
Find 15 treasures