moving the pieces cause them to rotate (to the correct position). Doesn't that make the puzzle super easy if you know how everything is oriented?
I might have to make this an option, but waiting to hear from more users on this before deciding.
Perhaps five difficulty levels, have auto-rotate for the first two, and make the final two levels only available to winners of a third/fourth level puzzle.
Personally, I'd be happy with either method, but this middle ground hits an uncanny valley, and makes it too difficult to visually recognize which pieces have already been auto-rotated. It'll basically just encourage folks to click on every piece to start with, which is a lot of extra clicking.
Perhaps this could be a simple button that the users can choose to click instead of a configuration?
Another suggestion: It can be a bit hard to see the shape of pieces with a dark colour, on a black background. Perhaps you could add an outline when you click on the piece to make it clearer? I know we can switch between light and dark background, but the white background on a large screen can be a bit too much