From what I understood of the Developers Room after beating the game with only Serge, things have to be done in a certain sequence there; certain things must be done within the game to access certain content and certain content of the developers room can only be accessed by performing appropriate actions elsewhere in the developers room. It was the principle behind the CT developers room, but they were stinted by the technology of their time. So, too, were the developers of the time stinted when making CC's Developer's room. However, they did have the technology to make it somewhat what they wanted of it. I never put much time into expanding on this theory or checking it out to verify it. By the time I got to the Developer's room, I had already put in the time to get all 44 characters, including Harle, and beaten the game for every ending.
It's a strange place that kind of drifts between dimensions, like Gaspar drifted between times in CT. Think strangely.