To get back up jump up from under the sphinx and press climb. I originally put a helicopter at the left bottom where its just walking into black. It was intended to use the other wildcard failing to win but I didn't finish the helicopter in time. In retrospect I would add a collider wall at the bottom of that corridor so you cant walk left there. So yeah its just a pitfall basically, and you have to jump up to climb the sphinx to get out:)