Here is the full list of all 30 Terraria achievements worth 400 gamerscore. It takes around 80-100 hours to unlock all of the achievements on Xbox 360.
The Guide has moved in!
Enjoy the view.
You have survived the Blood Moon!
You have begun the tutorial!
You have defeated The Destroyer!
You have defeated The Twins!
You have the maximum health and mana!
You have defeated Skeletron Prime!
You can only go down from here!
Looking good!
You have defeated the Goblin Army!
You have survived the first night!
Get every NPC to move into housing.
Reach the bottom of the World.
Defeat every boss.
Kill every type of slime.
Unlock Hard Mode.
Corrupt most of the World.
Hallow most of the World.
Travel 42km on the ground.
Remove 10,000 blocks from the World.
Find ALL the pets.
Complete the tutorial.
Activate 5 buffs at the same time.
Craft 300 items at an anvil!
Smelt 10,000 bars of metal.
Obtain every type of armor.
Place 100 wires.
Use every crafting station.
Travel from the surface to The Underworld and back without dying.