I started working on a game in early 2012. I got fairly far but after the engine by hand, I found I was doing a lot of manual creation for tile-map layouts. I stalled. Then I discovered a map engine that could be used with Cocos2d. Awesome. I ported it over. The touch controls just didn't feel good. I stalled. This weekend I rewrote it in Unity. Both in the original and in the tile-map versions, I simply had some files that contained all the map data. So I figured I'd do that with Unity. One scene per room. But that felt clunky and silly. Plus, every time new room would load the controller would stop taking input on anything held down. Not cool.
So now I'm doing it how I think it should be done in Unity. Each room is a GameObject and they get activated and deactivated as the player enters (and thereby leaves) rooms. And it works! I had to fix some math for bounds checking, but the camera just dances around the scene as necessary. Which should allow me to do some cool ideas I wasn't sure how I was going to handle if each room was a completely separate entity.