Punch a tree until the block of wood pops out.

Build some bookshelves to improve your enchantment table.

Harvest some leather.

Open your inventory.

Knife an enemy without him ever knowing you were there in Single Player or Special Ops.

Befriend five wolves.

Use a saddle to ride a pig, then have the pig get hurt from fall damage while riding it.

Bake a cake using wheat, sugar, milk and eggs!

Construct an Enchantment Table.

Destroy a Ghast with a fireball.

Acquire diamonds with your iron tools.

Use planks and sticks to make a sword.