We are currently refining the puzzles, including the images, materials, shaders, scripts, and where necessary, the puzzle mechanics.
This time, we refined the first puzzle we made, #1. We reselected the paintings we used based on image quality, color, and licensing. The paintings are clues to the puzzle, but the one we selected this time had some parts that were hard to distinguish, so we created a shader to momentarily highlight the clues.
However, since it was the first one we made (about 3 years ago), the modeling of parts and scripts were crude, so we tuned those parts properly.