I think there is a new secret room. im pretty sure there is a new door in the acid door room. Idk how to get to it or open it though. I tried the black, red, blue keys. And the one key from the rust area.
You can see inside of the new secret room through the new corridors windows. New corridor is between the acid room and the endless hallway room fyi
I can't even reach the door that leads to secret room, it's blocked by desks.
I cant reach it either but you can still interact with it at a certain angle
