Looks very nice and intuitive. Some puzzles are quite easy and some will take some time. The hints are somewhat transparent, but when you're stuck on a puzzle, you can only skip it and that's a shame, as I'd like to know how to solve in the end.
I surely hope that we'll get some more levels added every once and a while for the €5,49 it's quite a lot for an additional 12 puzzles, as the replay value is minimal when you've completed a level.
Nice game to kill some hours with, worth the price with new future levels only.