I'm in the thick of my third game (first original project) and I've never really had this problem before now: I'm not bored of my current project, I'm actually rather enjoying working on it. But I'm also considering ideas for my next project. I know what I want the game to be and I know what I want it to be about, but the gameplay and the story is still pretty abstract and I enjoy theorizing it and ironing it out.
Here's my question: is it unhealthy or just a bad idea to even think about my next project before the next game is either complete or mostly complete?