Secret Wolfenstein 3D Levels
Hidden Wolf3D levels in the Nightmare chapters.
Secret Wolfenstein 3D levels in Wolfenstein: The Old Blood.
All nine levels from Wolfenstein 3D's 'Episode 1: Escape From Wolfenstein' are hidden in the nine Nightmare chapters of The Old Blood. In each chapter, look for a secret room with an empty bed, a light and a Wolfenstein 3D poster. Walk up to the pillow to show a 'Nightmare' message, then hold [Action] to activate the bonus level. After dying in it you wake up in the bedroom you started from and can replay any Nightmare level.
1.Secret Floor 10 in Wolfenstein 3D
Start the first Nightmare level from Wolfenstein 3D. Go to the room at the end of Floor 1, near the Floor 2 elevator. Turn right and search the wall for a hidden room. Search the walls inside to find an elevator that reaches Secret Level 10 ('Floor 10').