It becomes hard to rotate the pipes on higher levels, since the tiles are smaller and smaller. But everything else is good, the sound is relaxing, the look of the game is nice, and it was a nice time-killer :-)
Reminds me of an old Soviet pocket game :-) in that game you had to deliver cosmonauts over a crater with a moving bridge, it was very similar to this one :-)
 "Pipe It 2D MOBILE"){kind=icon}
 "Fat Slice Mobile"){kind=icon}
 "Flood Fill Mobile"){kind=icon}
 "Pel Plus"){kind=icon}