Mythago Wood is a trippy series, with myths and reality blending. I'd suggest a light-weight, indie system like Prose Descriptive Qualities as a base. HeroQuest from Issaries (not the MB game) is another possibility, and, from what I've heard, Dogs in the Vinyard might work as well.
"On two occasions I have been asked [by members of Parliament], 'Pray, Mr. Babbage, if you put into the machine wrong figures, will the right answers come out?' I am not able rightly to apprehend the kind of confusion of ideas that could provoke such a question."
- Charles Babbage (1791 - 1871)