Here is the full list of all 53 The Basement Collection achievements.
Complete Spewer Bonus Chapter
100% the basement collection
Complete the Unknown in Time Fcuk
Complete chapter 2 in Time Fcuk
Find and collect all the lost larva in Triachnid
Unlock all bonus content
Complete Triachnid
Get XXXXX points in one playthrough in Grey Matter
Beat Expert Mode in Grey Matter
100% Meat Boy
???
Complete bonus chapter in Meat Boy
Complete chapter three in Meat Boy
Collect 16 bandaids in Meat Boy
Collect 8 bandaids in Meat Boy
Collect 4 bandaids in Meat Boy
Create and play a custom level in Spewer
Complete chapter two in Meat Boy
Beat Boss Rush in Grey Matter
Beat Mormal Mode in Grey Matter
Complete Spewer Chapter 5
Find the Lost Bird
Find the Demon
Find the Skinless Boy
Find the Crybaby
Find the runaway
Find the Glutton
Find the lost spaceman
Complete Spewer Chapter 4
Complete chapter one in Meat Boy
Complete Spewer Chapter 3
Complete Spewer Chapter 2
Complete the game the right way in Time Fcuk
Create a level in the editor in Time Fcuk
Finish the Game
Discover the Moon of Earth
Discover the Moon of Gravida
Discover the Moon of Debasa
Discover the Moon's of Bibulon
Find the Paradox
Get XXXX points in one playthrough in Grey Matter
Come full circle in Coil
Complete Spewer Chapter 1
Complete the game the wrong way in Time Fcuk
Make even more progress through the main game in Time Fcuk
Make more progress through the main game in Time Fcuk
Make progress through the main game in Time Fcuk
Get XXX points in one playthrough in Grey Matter
Discover the Moon of Malaisus