What Unlocks What?

Playing through The Basement Collection, I see that completing specific games will unlock hidden content. However I'm unclear as to what type of star unlocks what (translucent, white, black), and if there are additional hidden unlocks available. Are the unlocks based solely on completion of the advertised games (Aether, Coil, Meat Boy, Time Fcuk, Triachnid, and Grey Matter), or are there additional unlocks to be found (for instance getting a white star vs a black star on a game).

Solution 1:

The unlockable content in the Basement Collection only requires a white star to be obtained on the respective game that unlocks it, obtained simply for beating the main core sections in each game.

A black star, on the other hand, won't unlock anything beyond this extra content. It's simply an indicator that the game has been completed fully (100%).

The content unlocked is as follows:

• A.V.G.M: An extra unlockable game featuring a light switch in a room that has to be clicked for a couple hundred thousand times. Bonus content includes a deleted scene from Indie Game: The Movie featuring AVGM and several other boxes locked by a fake DLC barrier as a joke. Unlocked for completing the game Coil.
• The Box: A collection of drawings by Edmund McMillen when he was a child. Bonus content also features photos of himself as a child. Unlocked for beating the game Aether.
• The Chest: A collection of random sketches and illustrations by Edmund McMillen based on his games. Bonus content includes a File Explorer popup link to four other extra games hidden with the SteamApps game folder. Unlocked for beating the first chapter of Time Fcuk.
• Thicker Than Water: A comic created by Edmund McMillen in 2000. Unlocked for beating chapters 1-5 of Spewer.
• The Lonely Hermit: A comic created by Edmund McMillen in 2000. Unlocked for beating Triachnid.