SetGamePlayerControlGravityActive()
When I tested to see if this turned gravity off or on,
it seemed to have no affect on anything that I can see.
And I spotted a bug in the game engine.
If you set gravity very low (whatever you set it at),
the falling damage is always the same. (if the distance
of fall is equal).
But this does not jive with real world physics. If someone
went to Phobos and jumped off of a 15 meter tower,
it wouldn't be very painful- I'll bet, at least compared to the earth.
I think GG registers the hurt fall according to distance
fallen and not impact speed. That would be my guess.