I'm pleasantly surprised by this - it's a lot more satisfying than I was expecting. It's not quite a replacement for sliding-block puzzles because you can quite easily shift full sections around and that makes it quite easy, but for the purposes of making a PC jigsaw? You build sections, and then put them into position, and it's quite friction-less.
It's the sort of thing I'd happily play on a 5-10 min bus journey on my phone, you should consider a mobile port!