A word of advice from what I've seen:
How many people you kill and the amount of panic you cause has an effect on later levels. A non-lethal play style will mean that there are less rats around, and I think I read that there will be less guards and tallboys. Apparently it is worth playing it at least twice, once where you try to kill nobody and be as silent as possible, once where you just massacre everyone.
I haven't played any of it, but that's what I've picked up from playthroughs and reviews.
Don't forget all the branches that would require other playthroughs. Almost all major choices usually supply you with a lethal and non-lethal options, and it'd be worth it to see how different combinations of consequences would change how certain events happen.
Not to mention the absurdly difficult achievements, like Clean hands (No kills), Mostly Flesh and Steel (Never using supernatural powers except Blink I), Shadow (No alerts in the ENTIRE game), and Ghost (No alerts or kills in the entire game)
The one intentional kill was the duel at the party.
Did you know that you could use the crossbow sleeping darts?
I did use them, I took out several people that level using the sleeping darts. I didn't even realize one died somehow until the end of the level where it old me "one hostile killed". Since I didn't really care about achievements (and had killed one other person anyway), I decided not to replay the whole last level. I still got the good ending, at least I'm pretty sure I did.
I meant that you could use it in the duel.
I did not. And my second playthrough is full psycho. Good to know, though, thanks.
Whether or not you save Emily determines whether you get the world is ending or just the depressing one...thankfully I saved right before, so I went back and saved her and saw both.
Rented it for a few days. Really liked it!
Though because I can get fixated really easily sometimes, levels took FOREEVEEERRRR. Because I was really hard-pressed not to sneak around and choke out every single person, so I could explore every last nook and cranny, and nick ALL THE LOOT.
Hell I cleared out the Bottle St. Boys' distillery the first go through, and I didn't even poison the bloody still. Because as much as it was something of a racket and they really weren't the best people by any means, once I considered the scope of their operation I couldn't bring myself to plague all their customers.
Until the PURGE MINE ENEMIES playthrough anyway.
Anyone pick up the DLC? Just acquired it myself, haven't had a chance to play it yet.
[fifteen months later]
Yep, got the Goatee edition off the Steam sale, was the cheapest way to get the Knife of Dunwall and Brigmore Witches. So far I only played the whaling factory mission, that one is really cool. I decided to go full-on lethal this time, just to make it differently from playing Corvo (that bleeding-heart pansy) but the powers and weapons are actually more balanced when it comes to lethal versus nonlethal now, whereas in the main game they're heavily weighted towards lethality. That makes playing Daud as a murder machine slightly less effective, but still viable.
I also liked that at the end of the mission, my companion comments: "I've seen you kill a man without ruffling his hair. This time you killed the entire neighbourhood." Glad they kept those little comments on your playstyle up in the DLC.