Good but...GAME MUSIC?!
This is the ONE time I was thinking "Bah where are the sound effects?!" The music was on but then, I heard nothing while playing the level. It was quite fun and it got minimally challenging. But fix it so it has music or something (That of course, people can turn off to their whim) or some sound effects so we know we're pushing the pipe?
Overall good job. 4/5.