The Hidden and Unknown Achievements Here is the full list of all 25 The Hidden and Unknown achievements.Filter Achievement View View Image viewList view Sort by TrueSteamAchievement desc TrueSteamAchievement asc Achievement name desc Achievement name asc TSA Ratio desc TSA Ratio asc Gamers desc Gamers asc Steam order Date won desc Date won asc What are achievement flags? Click to find outApply The ChoiceSometimes, choice is only an illusion. ApologueThe future is not so bright, if you don't fight. PrologueThe "Good" Old Times. Chapter OneThe Bottom. Chapter TwoThe Rock Bottom. Chapter ThreeFrom The Bottom To The Top. Chapter FourThe Real Challenge, or is it? Chapter FiveYou are close. Chapter SixYou got far. EpilogueThis is the end, or is it? DisciplineYou have read the credits. The ResearcherYou have read it all. Introduction to 21Think. 21: Remembrance OneThe Black Swan. 21: Remembrance TwoThe Blitzkrieg. 21: Remembrance ThreeEfficiency. Extroduction to 21Think first. Introduction to 23Feel. 23: Remembrance OneDepression. 23: Remembrance TwoLove. 23: Remembrance ThreeHate. Extroduction to 23Feel second. 21 Without 23Thinking without Feeling is pointless. 23 Without 21Feeling without Thinking is dangerous. The GraduateYou have read all the main storylines in the game.