Right now, it works like this: you walk up to a door → press E → the screen switches → you appear in the next room. This is a noticeable break in the game flow. But we're gonna replace doors throughout the game with portals. No pressing keys, no darkening, no loading screen. You just walk and go through.
You'll be able to slow down, peek into the next room, stand on the threshold, and quickly step back. Everything should happen without interruption.