Polypheme is a prototype based off of a larger project. Polypheme is a mostly a tech demo used to demonstrate a scifi world spanning hundreds of miles.Polypheme isn't intended for commercial production though it is possible.There are many routes linking Polypheme to other places, which means that it doesn't have much commerce.
One of the routes (Route 21 south) is a water route so they get almost nothing coming in from there and the other is the only place where they actually travel on, Route 1 (North). The main trading district is 57th Street, where they get their supplies as there is no META-mart or hospital in the town (though in the game, your mom heals you). This is where you start out.