In addition, there are several pieces with blank backgrounds only, hence they all look the same, yet they are unique and the solver is expected to figure out where they go, somehow. If that's not enough, the Finished image is not easily accessible. Guess you're expected to have a photographic memory. Puzz3D Notre Dame has a good one, a stained-glass window. There is no reference image, but the edge pieces are easily identified, and the picture is not hard to figure out on the fly.
Several websites offer sliders online.
The Balmoral site is a slider-solver program. Unfortunately, it only handles up to a 3 x 3 grid. It's easier than running the solver. The content of this document may not be altered in any way without the permission of the author. Any proposed changes or additions to the walkthrough may be submitted to Tally Ho .