Goto your Shared Documents, find Monolith Games, then goto Save, keep clicking til you see a bunch of folders. Click on the one that says "Slot01" or something, in it there should be a SAVE file. Open that with a hex editor, and look for the text "DemoModeInvulnerable". Right after you find that, you'll see "0.000000"Change that to "1.000000". Get it? When hex editing, 0 means off, and 1 means on. And if you find any things about force, increase their values, it'll look cool. Like now when I jump kick people, they get blasted across the room. Man I'll piss my pants off if I manage to kick someone's head off, or kick their body in off.
Update: Open up 010 hex editor, and search for the keyword "force". Hit Ctrl+F to find it, and make sure "Match Case" is NOT checked, it will make it extremely hard to search for anything. You should find things like PRBForce, BodyDeathForce, PRBForceCP, BodyDirDeathForceScale, BodyDeathForceScale, and PhysicsBulletForce (ooooooh). You can experiment with those and change the value of one by a lot and see what happens, then go back and change another, etc etc until you've done it to all of them. Or you can be like me and just increase the values of ALLL that stuff and see what happens. I've already changed those, and now I'm gonna look for some more interesting things, like maybe how to get infinite slow motion.