You can see how our mechanic works in the two screenshots below. If the player looks at the object from the angle it is projected (like forced-perspective art), the object becomes real and interactive.
These are a few logotypes I toyed around with while trying to define a visual style.
These images show the process of designing the levels. I was mostly in charge of 'beautifying' the levels, making them more accessible and understandable. Most of the functional design was done by someone else.
Before you read on, have a look at a quick playthrough of this level:
Because of practical reasons, the level needed some editing in geometry. Lights and support pillars also made some places more noticable and attractive, and the corner with the box was made brighter because playtesting proved that players didn't know if it was useful, or didn't even notice it. We also added wires from buttons to doors, so the player always knew which button opened which door.
One example of the three stages all our levels went through, from only functional elements to a finished room: