Don't l let the player to leave one place for another before he finds "something" that exists inside the "hidden" or "locked" or whatever, room. That's the only way to make the game more interesting for him. Adding more empty rooms, or achievements (who cares about achievements, anyway) you get nothing... As I already told you, there MUST BE A REASON to search an area more carefully... ...

I've completed the game but I have no idea where the secret room could be. Any hints?

Does Neurosis have a point or an ending? I can't open or interact with anything, so I don't know what I'm supposed to do (if anything).