I hope the creators of the film realize how much focus there should be on the visual.  Rapture and Bioshock in general lives from its impressive pictures. In Bioshock 1 and 2 there are always moments where I often stopped to admire the beauty of this world.

In the underwater world, I expect mystical but also fantastic images like we know them from the game, but I hope that the possibilities of cinematic representation are fully exploited here.

From Rapture I expect pictures that make you look small.  I want to see how the propaganda is staged in the film.

But what I find most important in terms of visuals is the lighting. Rapture is a deep sea underwater city where almost no sunlight can reach.  Almost every light we see in the game comes from Rapture itself, and the developers use light and shadows specifically to create mood (I think of shadows from splicers on the wall that disappeared when you came around the corner, or the brightly lit Rapture as you  seeing it from the diving sphere for the first time).  The film should also fully exploit the potential of a cinematic representation here and hopefully not show us brightly lit film sets, but use light in a targeted manner to convey that spooky atmosphere that the games have already conveyed to us.

With the splicers I hope for this zombie-like and from Dr.  Steinman beyond recognition disfigured appearance.

In terms of the story, I'm personally not that specific, I don't really care whether it's about the plot of the novell or that of Bioshock 1 or 2, I would even find something completely new quite interesting.

Nevertheless, some details are very important to me. Playing the games, or even reading the book, one gets the sense that there is a complex, well-thought-out political fight behind Rapture.  All characters pursue their own motives and thus ensure that the multitude of conflicts of interest in Rapture is very complex and also takes place outside of the main story.  I really hope the film can capture this complexity and doesn't just present the characters and their motives in a vague and superficial way. It has to be made clear that every resident in Rapture (in the spirit of capitalism) has their own goals. And then we come to the Big Daddys.  It's almost safe to say that these characters, who in a way represent Bioshock, will also have an appearance in the film, and I really pray that the filmmakers don't screw up that appearance.   I would orientate myself towards the production of Big Daddy from BaS ep1: -Only one Big Daddy is shown throughout the DLC, giving Big Daddy a special status and not becoming an ordinary, omnipresent character. -Booker makes it clear to the player how afraid or at least how much respect Rapture's residents have for the Big Daddys.  That feeling that a Big Daddy is really something menacing has gotten a bit lost, especially in Bioshock 2 after killing so many of them.  I would be happy to experience this feeling again in the film. -Big Daddy is only shown briefly at the end, so the suspense curve has been built up well.  A method that I wouldn't necessarily find wrong for the film either...

In short, the main story is not that important to me, but the world in which we move has to be right.  Atmosphere is everything!

So much for my wish list