About ten years, actually. I spent nine years working on the 3-D version, but I couldn't find an artist to do the graphics, and my 3-D graphics aren't that great. I spent about a year on the 2-D version.
Speaking of thought, here is another important difference between Skefalia and the other precincts. You may have noticed that the other precincts that you have encountered so far each have their own vortices, but there is no particular vortex assigned to Skefalia. That is because, when we are thinking, we are not usually thinking about thought itself; rather, we are thinking about one of the activities represented by the other precincts.
Speaking of thought, here is another important difference between Skefalia and the other precincts. You may have noticed that the other precincts that you have encountered so far each have their own vortices, but there is no particular vortex assigned to Skefalia. That is because, when we are thinking, we are not usually thinking about thought itself; rather, we are thinking about one of the activities represented by the other precincts.