Having finally read it, I really liked the premise. However, I too would include this as a part of an on-going campaign, where players had to (or more like found it more convenient to) use a Jinteni portal to reach their destination.
For a one-shot, I'd need to have on hand or create a set of characters. I would have to make some decisions about their knowledge (or alternatively have them roll lore checks) about e.g. whether they realize the nature of the Construct or know how to operate the Portal.
I did vote for "Decent" because of my one-shot-critique. That said, it's an interesting adventure in Shadow World, and I'd like to see more.