A one-time 30+ minute Portal-inspired map for single player only. Contains heavy parkour, light puzzle-solving, and a lot of story and visuals.
Story?
This doesn't quite need a introductory story as you literally start off in the forest outside the facility, implying that you are either lost or simply exploring the forest only to arrive upon the strange testing areas of Atilliary Facilities.
The story is progressed and created there and then by the player's actions (albeit rail-roaded by the plot) and SADOS' reactions to the player's actions.
The player is meant to be clueless about Atilliary Facilities's backstory, though there are some hints scattered around the map in the form of story, scenery and one lab report.