Shadow the marble puzzle isn't that hard once you figure out how to move things around. There are five lasers that I'm aware of in the senior game and the only difference between junior and senior games is the number of lasers you have to block.
Do you see a little metal looking bar, should be at the bottom of the puzzle, on the left? That bar is how you move the marbles and the tile.
You may want to make a saved game before you start moving things to get an idea of how it will work.
Good luck
Sue