Gravity on axis x,y,z?

Tell me how to do the gravity on axis x,y,z in BGE?as in this video


This video effect is made ​​in this default mode, using the force on different layers
but I need to do it in the BGE

There is a way with python, look at scene.gravity

Example, invert the gravity:

import bge
bge.logic.getCurrentScene().gravity = [0,0,9.8]