Ken Levine, creator of System Shock 2, talks to IGN about his forthcoming RPG Bioshock. Two choice quotations:

I’ve always said that, when we were working on Thief, I’d rather have a story element about the moss arrow then about some cult you never get involved with in the game or some god or something. That’s because I play with the moss arrow, it’s part of my game experience; I want to tie that into the story.

and

I think it’s all about making a world that’s believable. One that has an aesthetic point of view in which the player isn’t constantly bumping into the edge of thus pulls him out of the experience. It’s not about physics puzzles, it’s about having things behave the way I expect them to. Half-Life 2 uses physics puzzles really well; that’s not an issue. My response is not to create my own gravity gun. Our goal is to make this world in Rapture a real place.

Yes. Yes, yes, yes. More sharp, incisive, intelligent discussion in the full interview.