How to get the “I am free!” achievements

All achievements are Secret Achievements in The Secret of Monkey Island: Special Edition, so here is the list of all Achievements and their descriptions. (source)

• The Three Trials
  Completed Part One: The Three Trials. Guybrush proved himself worthy to be a pirate.

• The Journey
  Complete Part Two: The Journey. Guybrush used a voodoo spell to travel to Monkey Island™

• Under Monkey Island
  Completed Part Three: Under Monkey Island. Guybrush traveled into the Monkey Head and got the root.

• Guybrush Kicks Butt
  Completed Last Part: Guybrush Kicks Butt. Guybrush stopped LeChuck from marrying Elaine Marley.

• Sharp Tongue
  Guybrush learned all of the insults, and is the wittiest/deadliest pirate what ever swung a sword.

• Ten Minutes Later...
  Guybrush can hold his breath for 10 minutes, but not any longer than that.

• Escape Artist
  Escaped from the monkey island cannibals hut 5 times.

• RecordKeeper
  Collected all of the notes and memos sent between Herman Toothrot, LeChuck and the Cannibals.

• Human Cannonball
  Finished the entire game in record time. We hope you were wearing a helmet!

• Old School
  Experienced the original, classic adventure game, as it was in the early 90s.

• Determined
  Completed the game without using any hints.

• Marooned Everyone
  Re-marooned Herman Toothrot and marooned Carla, Otis and Meathook on Monkey Island™.

The update notes say:

• Added 4 more achievements along the same lines as the "Medium Rare" achievement added last week
• Renamed "Medium Rare" achievement to "Medium Well"

Since they are along the same lines as the previous achievement, they mean the player should complete both the light world and the dark world of a chapter, and the sum of the best times for that chapter should be lower than some threshold. Here are the descriptions of each one:

• Rare - Spend as little time as possible in The Forest (around 320 seconds)
• Medium Rare - Spend as little time as possible in The Hospital (around 430 or 460 or 490 seconds)
• Medium - Spend as little time as possible in The Salt Factory (around 570 seconds)
• Medium Well - Spend as little time as possible in Hell (around 500 or 550 seconds)
• Well Done - Spend as little time as possible in The Rapture (around 740 seconds or more)

About the old secret achievements:

• Suffragette - Complete the light world of the Cotton Alley
• Seneca Falls - Complete the dark world of the Cotton Alley
• Well look at you! - Input the petaphile code to play with Tofu Boy

Sources:

• Super Meat Boy Wikia
• SteamStats
• Steam Forums

Note about the times for the achievements: Many people use Super Meat Boy Stats (old repo at Google Code, new repo at GitHub) program to find out how much time they have spent on each chapter. However, the reported total time is not exactly accurate because "it counts 15 secs per completed warp zone", and people posting their total times didn't mention if the warp zone time has been subtracted or not. For this reason, the times I posted above might be quite inaccurate.