Colors of V

What you cannot see cannot see you!
Invisible is not hidden. It is absent. A wall you cannot see is not solid and you walk straight
through it. A trap you cannot see cannot cut you. An enemy you cannot see is frozen — and cannot
be shot. Visibility and collision are the same channel, so they can never disagree with each
other, and every gel swap rewrites the floor plan under your feet.

A vector dungeon on a monochrome tube, lit by three subtractive colour gels. Drop a gel and half the room stops existing: a wall you cannot see is not solid, an enemy you cannot see is frozen and cannot be shot. The colour channel is the collision layer, so sight and physics never drift.