Lights

The lights in are game will be fully lit rooms for most of the game except for certain parts will have key lights to draw you too the important objects or an area transition. In a top down perspective game the lights will be hard to show the source but how much light on the floor and were it is coming from is the focus of the light map for are levels.
The pipes if possible could have a greenish tone to them when there leaking to further tell the player that there a focus of the game and to tell them quickly that they already have repaired that pipe.

The janitors closet will have the light source be the door to show your in an isolated area and in a closet. The transition area between the offices and the factory will have dimmer Lights too.

The office area it self has mostly even item except for key points like the first weapon you can pick up ,the wrench, and special material.

The factory, warehouse, and lab have bright lighting and red emergency lights will highlight the important areas.