See Your Waist And Down:

On the level metropolise at the part where u have to board the scarab jump on it and kill all the people (grunts'jackels'ect) after you are done killing jump inside of the scarabs main gun and walk inside of it and if u walk far enough you should be able to see your waist down.

ps.sometimes you can shoot your waist and down part of your self.

pss.you cant really get out of it