Level 3
"Electrical Station"
Level 3 consists of a mix between Level 2 and Level 1. There are remains of pipes and building equipment from previous levels, apparently this level was supposed to be expanded. It's an Electrical Station, having a faulty power box that requires a restart upon entering.
Exiting requires that you get past the smilers, the power box is optional to restart unless you know the level's layout by hand. At the exit hallway, you can either choose to proceed to Level 1 Annex 2 (to be added) or risk yourself to The Fog.