When I was a kid I had one of those Electronic Kits from Radio Shack, and I loved it! This takes me back to those days! 🙂
I was having some trouble fitting the symbols into their spots.
I finally figured out it was because I was trying to line up the squares exactly. When i do this, the mouse pointer is slightly off the target so the game thinks I am in the wrong spot. (But visually it looks correct, so it's kind of confusing haha.)