Here is the full list of all 10 D.F.R.: The Light achievements.
Blow out one candle.
Beat the game.
Beat the game on "Nightmare" difficulty!
Beat the game on "Normal" difficulty.
Beat the game on all difficulty settings.
Blow out two candles.
Blow out three candles.
Blow out four candles.
Blow out five candles.
Teleport from the hidden conventicle.