Pornpipe combines the classic Pipe Mania gameplay, where you have to build a pipe of a certain length within the alotted time, with the gameplay introduced by the Pipe Dream arcade machine, where the main goal is to connect the source and drain, and the pipe length just gives additional points. In Pornpipe, you have to do both. First, you have to start building a pipe. After it has reached a certain length, a drain (in the form of an, uh, dickhead) will appear in the rightmost column. You can move it up and down, but have to build your pipe to the right-hand border of the playing field to meet it.
This is just the first level. After you've beat it (and it isn't easy), you are confronted with a level already filled with pipes. Instead of placing them, you can only rotate them. I never beat the second level, so I don't know whether there are any further surprises.
While they share the basic idea, Pornpipe is quite different from Porntris as a game, mainly because it really is a game. The gameplay is challenging and in some aspects original. The erotic element, which made the main, or make that only, attraction of Porntris, is more annoying than amusing here. Just as Marble Cooking, but for different reasons, Pornpipe might have been better off without it.