JUst wondering because it's such a fun game and i't would be sooooo soooo soo Pointless if no one has yet done this.
I don't think anyone has done this yet. But there are some modded gamesaves with a developer room and other stuff.
There is no dev menu for the PC version of them game, so there wouldn't be one for the XBox version. Also if it was possible to make ISO mods for this game, someone would have probably made them by now.