It's really good. The only thing I'd say is missing, is a real-time preview of the entire unfinished puzzle being built, instead of just the finished version.
Using the hands window is a bit awkward, but it is a great game and can use your own images. It needs a superhard version where you have to rotate the pieces but that is a bunch of programming logic to sort out. Maybe one day.
I felt in love with the "Create new puzzle" option: that allows infinite possibilities and a personalized touch. No music, (but who cares?). Great gameplay and configurable options. Easy to understand handbook.