The initial idea was to make a quick prototype of a randomly generated runtime environment. Meaning, instead of the world generating at the start of the game and keeping that design until it ends, VANISH would spawn just a few modular pieces of the world around the Player. As the Player moves, more pieces spawn in front of them and despawn as they move away; this means if the Player turns around and goes back the way they came, it'd be a different environment.
The game is supposed to be dark, it's a tunnel. The wall lights are spaced to the point that as soon as you can't see the one you've just passed, you're just barely able to make out the next one. This not only creates a dark, mysterious, creepy atmosphere, it builds up the Player's anxiety, emotions, and fear.
VANISH was created in Unity 4 Indie, so good dynamic shadows or lightmap baking wasn't a great option. Instead, VANISH uses realtime lights with no shadows. The wall lights have a point to cast general radial ambience and a spot to cast light against the opposing wall with a light cookie to mimic the shadow from the light's housing. Point lights are also uses in other areas (like the image below) to enhance certain effects; around sparks, glowsticks, radio.
The paper uses a custom shader that utilizes diffuse, transparency, normal, and translucency. With no lights on, only the transparency is visible to give the paper torn edges. With the light turned on to your back, so that the light is shining on the front of the page, the normal map kicks in and you're able to see some wrinkled shadows. When the player turns so the light is behind the paper, the translucency shows off the brilliance of the shader; showing the paper fibers, and in some cases - a hidden message. The paper uses just 1 mesh which is used as a prefab to spawn multiple within the game; all 'notes' are included in 1 diffuse with the alpha being the transparency, 1 normal map, and 1 translucency map.
Since everything spawns, and respawns, during runtime... we inserted spawn nodes for items like details, pipes, papers, and wall markings; this allowed us to reuse the same bare hall pieces and randomly spawn in details through code when/if needed.