Sewers

The Sewers is the sixth area the player visits in PA. This area has a major gimmick where it has rising and sinking acid that it uses in many of the stages. Living here are many Corroders and their boss, Corrosion. At the end of the sewers, there is a boss fight with Corrosion. Other than that, this section has many classic themed obstacles.

Design
The Sewers uses 2 themes: diamond plate and corroded metal. While the latter is much shorter than the former, it seems it was originally going to be longer due the corroded section on the map extending much further than 2 stages.