When you first looked up and saw another character that resembled yours i first thought it was some dimension with such weird geometry where you can see yourself and the world "mirrored above" yourself at all times. That's a strange idea, the geometry of the world itself wrapping around, such that you can maybe even interact with yourself from strange angles; Imagine a enemy attaching itself to your back and the only way to get rid of it is to shoot it off from your "mirrored" self. Interacting with yourself in such a way would sure be strange.
Gravity is always relative to each entity and has nothing to do with the environment; there is no global gravity direction, so it would only ever point down relative to your viewpoint. I might include a vertical view angle meter again, though I'd want to make it more diegetic as a HUD element.
