The Secret of Monkey Island: Special Edition

This is secret achievement called "The Three Trials" and it unlocks once you've completed the first of four chapters in the game.

I would strongly recommend trying to work out for yourself what to do if this is your first playthrough, as using a guide will spoil the game.

If you feel you've exhausted all options and don't know what to do next, check out this guide at GameFAQs - it covers the whole game.

http://www.gamefaqs.com/fmtowns/945224-the-secret-of-monkey-...

Credit to Antitype who wrote the guide.

Complete walkthrough of part one:

Full walkthrough of the game: