(and hardest despite its happy theme) chapter in Super Meat Boy. Instead of Meat Boy trying to rescue Bandage Girl, it's the other way around.
This is the only chapter not to have a boss, Glitch level, or Bandages (if the PC version is being played). Players will need to beat The Cotton Alley if they want the Suffragette (Light World) and Seneca Fall (Dark World) achievements and it will need to be beaten 100% if the player wants to unlock Meat Ninja and reach the final total percentage (102% for the XBLA version, 106% for the PC version).
The name of the song used for both the Light World and Dark World levels is called "McLarty Party People".
All of the "dark" world levels have a white background
The levels are sorted according to the chapter their hazards belong to. Levels 1-4 have hazards from the Forest, levels 5-8 from the Hospital, levels 9-12 from the Salt Factory, levels 13-15 from Hell and levels 16-19 from the Rapture. 4 Letter Word/Brag Rights could possibly be based on The End.