Chapter 1: Launch of the Screaming Narwhal

Bronze:

Leave Well Enough Alone
Objective: Experienced a brief, yet horrifying transformation

Why is My Older Brother Laughing?
Objective: Encountered a shipload of references to the previous Monkey Island games

The Sounds of Science
Objective: Heard DeSinge treating four different patients

Bats Right, Throws Lame
Objective: Repeatedly Threw Things... Kinda

Is That a Pox On Your Face, Or Are You Just Angry To See Me?
Objective: Experience the effects of the Pox on the charming inhabitants of Flotsam

Silver:

The Legend of LeFlay
Objective: Quizzed everyone about Morgan LeFlay

This Ain't a Library
Objective: Intensely browsed a prominent bookshelf

LeChuck Slayer
Objective: Defeated LeChuck (again)

Use the Source
Objective: Met Deep Gut

The Winds of Freedom Blow
Objective: Escaped from Flotsam Island

Gold:

Many Unhappy Returns
Objective: Found Elaine

Chapter 2: The Siege of Spinner Cay

Bronze:

Meals Fit for a King... Queen... Whatever
Objective: Gave the MerLeader every kind of bait

She's Cute When She's Angry
Objective: Get Morgan angry by repeatedly checking out the mast

Fishing for Literalists
Objective: Caught a Red Herring

Talk to the Hook
Objective: Threatened a number of adversaries with a Hook

Nice Try
Objective: Heard the Secret of Donkey Island

Silver:

Give Her a Hand
Objective: Kicked LeFlay off the Screaming Narwhal

Artifacts of LIfe
Objective: Get all of the Summoning Artifacts

Mighty Merperson Rescuer
Objective: Save the MerLeader from McGillicutty

Model of E-FISH-Ency
Objective: Read every fish joke

Ride 'Em, Pirate
Objective: Made LeChuck do something embarassing on the cliff

Gold:

The BIG Finish
Objective: Sailed to the alleged resting place of La Esponja Grande

Chapter 3: Lair of the Leviathan

Bronze:

The 0.01 Percent Solution
Objective: Got one one ten thousandth of the way through the alternate solution to the Cochlea puzzle

Frequent Tuber
Objective: Used all the Bile Tubes in all directions

I'm So Faced
Objective: Tried every possible Face-Off feature

Bongo Baby, Yeah
Objective: Played the bongos repeatedly

Meet Murray
Objective: Introduced Murray to everyone

Silver:

The Newlyfed Game
Objective: Convinced DeCava that Guybrush is married to Morgan

There is a Brotherhood of Jerks
Objective: Accepted into the Brotherhood

La Esponja... Grande?