Pipe Dream-esque games have always fascinated me. Hell, I even liked the hacking in Bioshock (there! I said it!). However, I can barely get my mind around Hyperpipe, which no only wants you to connect pipes, but do so without leaving any pipes unconnected.
Far from being frustrating, the game is actually best played with a cup of coffee and some Whisperings PureStream piano happening in the background. Kick it!