I'm VERY bad at these games (I was lucky to make it past the first level lol), but I really like this game's design. Music is good, very nicely composed, though the minor scale might be a bit too sad for this kind of game... that's just me though, there's nothing wrong with the music itself. My only real complaint is with the pipe highlighting - the green overlay is a little too subtle; it's hard to see what pipes are selected. Maybe alter the color of the selected pipes?