Chop down your first tree.

Build a house suitable enough for your first town NPC, such as the guide, to move into.

Obtain your first hammer via crafting or otherwise.

Mine your first nugget of ore with a pickaxe.

Discover and smash your first heart crystal underground.

Obtain an anvil made from iron or lead.

Discover a golden chest underground and take a peek at its contents.

Craft a mana crystal out of fallen stars, and consume it.

Equip your first grappling hook.

Defeat the Eye of Cthulhu, an ocular menace who only appears at night.

Using explosives or your trusty hammer, smash a Shadow Orb or Crimson Heart in the evil parts of your world.

Defeat the Eater of Worlds, a massive worm whom dwells in the corruption.

Defeat the Brain of Cthulhu, an enourmous demon brain which haunts the creeping crimson.

Discover a large bee's hive deep in the jungle.

Defeat the Queen Bee, the matriarch of the jungle hives.

Defeat Skeletron, the cursed guardian of the dungeon.

Steal a key from the dungeon's undead denizens, and unlock one of their precious golden chests.

Spelunk deep enough to reach the molten underworld.

Craft a molten pickaxe using the hottest of materials.

Defeat the Wall of Flesh, the master and core of the world who arises after a great, burning sacrifice.

Unleash the ancient spirits of light and darkness across your world, enabling much stronger foes and showering the world with dazzling treasures (and rainbows!).

Smash a demon or crimson altar with a powerful, holy hammer.

Mine a powerful ore that has been newly blessed upon your world.

Equip a pair of wings.