I would never have the patience to work on a 1000 piece puzzle which has parts that are almost interchangeable. I liked the puzzle of the United States in which each piece is in the shape of a state.
The Fluorescent Wolf puzzle was a gift from my children to my wife and it is finally complete, missing a few pieces that the cats hid. There are some extra pieces that don’t fit exactly meaning a few mistakes were made.
I did not help, but I couldn’t resist seeing it under UV light.