By now I imagine most people know there's an unlockable sword that will allow you to beat your enemies into unconsciousness instead of brutally murdering them, but this thread isn't about that. It's about the non-lethal option available to you from the start of a new game, and it is, quite simply, just disarming your opponents (Or dislegging, or even both if you prefer) and then letting them retreat from battle using optic camouflage. They'll require you to back off a bit, or else they'll keep crawling and/or stumbling at you, but rest assured your enemies will get the hell out of there when they realize how screwed they are.
I've been doing it for a few chapters now, and it's a blast; the battles get far more technical when you're trying to avoid splitting everyone in half, aiming to land non-fatal injuries while you're being fired at by rockets and swarmed by vicious cyborgs and the like. It means that you've got to be very on the ball when it comes to your swings, constantly aware of where the enemies are, and you're going to be passing up on all those delicious healing organs tucked away in your enemies' midsections.
It's not all bad, however, because successfully no-killing a section of a level scores you points towards your battle ranking- roughly as many as you'd get for not taking damage, in fact. There's also a bonus applied at the end of a chapter, if you've managed to make it through without slaughtering anyone, and the Unmanned Gears (UGs, if you weren't using your codec) don't count- Slice them to bits and use them to heal yourself all you want.
I just thought I'd let people know that there's a non-lethal option available even without tracking down the Men In Boxes to claim your wooden sword. If the game is feeling a bit too easy for you, give this a shot- it's fun, and hey, maybe you'll feel better about yourself knowing that no lives were lost in your pursuit of an S Rank.