Things you PROBABLY DON'T KNOW about Amnesia: The Dark Descent

Fact number one: Did you know Daniel is actually a ginger?
On the cover of the retail Amnesia, Daniel is shown as a ginger! Red hair with green eyes! he's also got regular length hair for the time (being cut to above his ears). The Daniel you probably know (Green or blue eyes, with shoulder-length brown hair) Was the first concept art that was released of him in 2009.

Fact number two: Amnesia was going to be called Horror Cabinet!
I kid you not! The infamous Amnesia was going to be called Horror Cabinet! This game was vastly different from the final game, and TWICE AS LONG AS AMNESIA. The content was cut due to budget problems. Horror Cabinet's plot was Daniel (who at this time still had long, brown hair) fell into the basement of the ancient castle Brennenburg. He calls it familiar, but can't remember where from. The plot is Daniel exploring the castle, struggling to piece together where the stray memories came from.

Fact number three: AMNESIA ALMOST USED A GUN
Don't you wish this stayed around? Yes, indeed, when the game was transitioning from Horror Cabinet to Amnesia, the monsters from wars had a VERY SMALL chance in dropping the Flintlock Pistol. Other weapons included a sword, a butcher's cleaver, and the torch that was later removed to make room for the lantern that's in Amnesia today. The weapons feature was removed to make Daniel (and the player) feel helpless to the monsters

Fact number four: Brennenburg's monsters were the corpses of the dead, re-animated by plants.
Well, it may sound odd, but old concept art of the monsters showed Bluecoats (NOT Redcoats) that had carnivorous plants that grew out of their mouths, stomachs, eyes and noses. This idea was not completely scrapped, as you can find the plants in a section of Brennenburg near the end of the game. The red mist that clouds the room they're in is actually their spores and pollen, which was going to be poisonous at first. But the room was too big to get through without dying, so the poison effect was taken away.

Fact number five: The REDCOATS were going to be intelligent
In the Horror Cabinet game, REDCOATS were monsters that retained their intelligence after being transformed. BLUECOATS were mindless, and attacked upon seeing Daniel. This could be an insult, as the "Redcoats" Were British soldiers, while the "Bluecoats" were meant to be American Soldiers.

Fact number six: Horror Cabinet had an outdoor section.
Horror Cabinet began by finding Brennenburg, meaning Daniel and the player were probably outside before the plot of the game began. This idea was probably what made the producers put an outdoor section in the upcoming Amnesia, A Machine for Pigs.