Was playing it recently, having gone a bit past the Opera boss, and it is a fun game indeed. It has hints of the bland walking simulator/interactive movie style that the major games were going for around the time, but still the game feels like the authors were going for what they wanted, and that outshines the potential blandness.
Also regarding putting whatever the devs wanted, on each boss so far it feels like someone asked "wouldn't it be fun if..." and the others went like "sure, do it".