Now that I think about it, the subspace is a really cool idea/invention (if it weren't for it being Gideon's creation).
Your emotional state manifests into an actual, physical place where you can wallow in whatever emotions you're feeling. It can be accessed by anyone with the knowledge of how, and can even be used as a form of transportation. It's like a wrinkle in time; by shortening the distance, you can shorten the time, also. Though I've always wondered what means Gideon went to to create such a broad dimension... that's for later.
I've been wanting to put this concept into a work of fiction that doesn't necessarily have to do with Scott Pilgrim. I've been thinking of making a cool study guide or manual to it, too. This would be a fun way to use my time. I would make my own special concepts for it, while also using the ideas from the series. I would, of course, change them a little to what I think is good, but that's okay. So, if anyone has any theories about it, please say so in a comment.