I, personally, ask for only two things:
1. Story depth. The general story of Dishonored was pretty solid. Unfortunately, it was very shallow in regards to twists and emotions and was very predictable. This could have easily been fixed by some added non-Emily emotion, such as a romance, and/or by some build-up on the mysticism of the game. In this first game, you have to read a bunch of notes and books to learn anything about the world.
Emotion - I will admit, Emily was done very well. Although it could have been more prevalent, your choices directly reflected Emily's developement, considering you are her father figure. However, making Corvo simply an assassin that happens to have a young girl that trust him is... meh. Addding additional characters that you should give a crap about would really give the game life. A love interest, maybe several (think Mass Effect), would really be a big help. In Dishonored, Jessamine is the only LI, and she dies in the first five minutes of the game. With the added element of Emily, an LI could have caused conflict (drama, ho!).
Mysticism - One word: Outsider. He had the potential to be an amazing plot device and psuedo-villain (make you hate his neutrality). Dishonored make you inquire about his role, origin and purpose, but never gives you an answer. In a Dishonored 2, he needs more significance in the story. Greater role and fleshing-out of the Overseers would have added to that as well, considering they are like the steampunk version of the medieval Catholic Church. Both of these entities need more focus and emphasis on moral ambiguity. Also, the "Chaos" needs more effect AND cause. If I silently kill a bunch of dudes, and hide their bodies, why does (spoiler)*? Shouldn't there be an underlying reason for that? Shouldn't those things be the result of "Chaos" not "killing"?
2. MOAR CONTENT. Any game that take less than a day to beat needs MORE. I got this game for FREE because my cousin was so disappointed. The sandbox-style missions are awesome and all, but the game still feels too constricted. I mean it only takes about fifteen hours to beat the game if you're not going for particular achievements.
Size Matters - Sandbox missions: Awesome. Nine fixed missions with no free-roam: Not awesome. Dishonored feels almost like Deus Ex: Steampunk. At least DX took you other places in the world; Dishonored give you eight fixed locations in Dunwall to explore go kill/neutralize someone in.
Length Too - Innuendos aside, you can beat this game between sunrises on your first play-through. Second, third, and forth times take less than half of a day.
So, yeah.
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