"Bonus Images" option:
Successfully complete the game to unlock the "Bonus Images" option at the
main menu. Select it to view development team photos and character artwork.
"Director's Message" option:
Successfully complete the game to unlock the "Director's Message" option at
the main menu. Select it to get a message from Charles Cecil.
Successfully complete the indicated task to unlock the corresponding comic page.
The comic contains the game's prologue and can be accessed from the main menu.
Page 1: Examine Carchon's bookshelf twice with Nico at the start of the game.
Page 2: Show the sewer key to Guido in front of the Hotel Ubu.
Page 3: Use the sewer key on the tripod at the Crune Museum.
Page 4: Show the sewer key to Khan at the top of Bull's Head Hill.
Page 5: Use the sewer key on the skull door under the sewers of Montfaucon Square.
Page 6: Use the sewer key on the suit of armor in de Vasconcellos' house.
Beneath A Steel Sky reference:
Progress until George is outside Rue Jarry. Drag the sewer key onto the apartment's door, then to the old woman at the flower stall. Tap on the second window on the apartment's third floor to see a room that is based on Beneath A Steel Sky.