Beautiful game. I love how different choices changes some dialogue, but there's not really a difference besides the outcome of who gets to say what.
The extra residential section seems unnecessary. I can only assume it's there to establish the steampunk vibes and the detail is astounding. It did however throw me off my first play through when I had to find the victim's apartment because (1) that section wasn't closed off even though the train section was and (2) it was the first place I checked since it easily matched the description of a place where the victim would live as well as how they died. In short, I did not except a tiny one-story looking balcony to be the scene of the crime. I still wouldn't shun the beautiful graphics for that section since it did help establish the game's universe, but did not by any means involve the actual story.
Same thing could apply for the train station I suppose. A cut scene would have sufficed since the actual area had no use (other than that odd bit with the mouse).
If the purpose of having all that walking space was for players to get immersed in that world, there would have been other ways to do that without creating those unused areas. If detail was what you were going for, mannerisms, local slang, and even terminology to name a few would equally captivate players. After all, you did say this was "a story focused game", and dialogue is a really important aspect of stories which would have been incorporated anyways.
By absolutely no means am I trying to discourage all of the hardworking people that made this game, because the game is fabulous! I'm just hoping some constructive criticism and suggestions would help improve games like this because if quality and effort like what I just saw got fine tuned, it could make games that were good, become far greater.