Currently, I'm trying to do a non-lethal playthrough. I've gotten through the prologue and first chapter, but I couldn't go kill-free through them. During the prologue, I was still getting used to the stealth gameplay, and with no way to run away, I had to either kill or restart. During the first chapter, I ran out of sleeping darts and I accidentally aggroed 3 guards at the same time; I panicked and instead of running away, I hacked them to pieces xD
I also had one incident where I snuck up on a guard and went to choke him for a non-lethal takedown, and my brain spaced out, and I hit the right-mouse button for a sword kill. I was like "... oops." lol
Right now, I'm thoroughly enjoying the Blink skill, and I'm making liberal use of the Dark Vision ability, though the lighting when I use it kinda gives me the creeps. I've used the time freeze skill a couple times to good effect, but it takes a crap-load of mana to use (well, I think it's actually called Adrenaline, but whatever, it's the same thing lol), so I don't use it very often.
Is anybody else playing this game? What sort of playthrough are you shooting for? What playstyle are you using, and what skills/weapons/equipment are you making the most use out of?