I made a quick mockup of our current design of the first level. keep in mind this is the player's first introduction to this game and we want the player to figure out the machanics on their own - so it's a very simple "puzzle" (it's in parantheses because i can't claim it to be puzzling in any way).
Let me first introduce you to the basic gameplay.
The hero - Claire (working name) is a lucid dreamer. Her dreams are governed by light and darkness - Claire perceives the light to be a symbol of her consciousness and control, while the dark is less controlled areas where she is more suceptible to her subconscious emotions.
The character's abilities are affected by the light condition - in the light she doesn't jump or run, but she can interact with objects and break glass and wood surfaces. In the dark "mode" she can jump very high and run fast, but cannot interact with objects.
Claire uses a red LEVER to switch the lights on and off in certain areas where "Light Slots" are available.
The first level
player enters level, sees a dark tunnel ahead and automatically goes there. upon closer inspection, the player realizes he can't go in (we haeven't decided on the nature of the obstacle yet) and looks around a bit more. sees the Service Tunnel to the right and goes in. it is lit. at the end of the tunnel the player sees a panel with a bright red lever and being curious and clever goes to inspect it. the player then learns he can interact with this lever. so he does. the character pulls it out of the panel and - me oh my - the light goes out! Oh noes! in the dark - the tunnel changes - as does the character. the player learns that the dark avatar allows him to jump and run - unlike the light avatar, which limited him to walking fast. with the lever in hand, the player jumps his way out of the creepy dark tunnel and goes back out into the main hall, where he sees a similar panel to the one where he found the lever. at this point he's supposed to put two and two together and stick the lever in it to light up the main tunnel - at which point it changes form and the obstacle is removed, allowing him to exit to the next level.