I noticed a render of what I think is pinned to the wall of the office. It's the second picture from the top and is alongside other character renders -- you can see it when Mark is being interviewed.
I also noticed a on a piece of concept art. The mouth was open and it looked like an entrace to a cave (maybe the hub world). Could this be the face of the main antagonist?
There was also a , which could be an early , with . It appeared to be a .
A new level model was being worked on. It was untexture, but looked like a large building/temple exterior with platforming elements leading to the top, and I think it had a few entrances leading inside the building. , ,
Sorry for the terrible picture quality.
Edit 2: I've just realised all my image URLs have expired, but you can find everything on the YouTube video manually.