I am writing a game in Inform, which is currently called “Space Quest!”, but the name will be changed since it is copyrighted. In Space Quest, the PC is a robot, who has the power to transfer his mind to other robots, using ChangePlayer(). Is this a good idea, and has it been done before?
Well, it’s an idea. There’s certainly nothing wrong with it. What really matters is what you do with it - how you flesh it out and incorporate it into a game.
I think the potential for multiple PCs that you can switch between at will is still largely untapped, really. But again, I think that what’s more important than whether you’re braving new ground is whether you actually come up with a fun and/or compelling game.