Less linear story and play experience. For instance, depending on how you traverse the castle, you will run into characters at different places and different times, and it can change the way the game unfolds. Also, an option to respond to characters you encounter in different ways, kind of similar to Mass Effect. I don't think you should have a "Good/Evil" meter, but the different responses can change how the story unfolds. Like, maybe you wind up fighting one Hugh/Maxim/Julius-type character instead of another one, and you also get different dialogue and endings. This type of thing should also change what paths open up for you in the castle. I'd like that a lot. It would give tons of replay value.