Yeah, you are younger than I thought! haha
I had fallen into a rut with my personal art a few years ago, and thought about trying digital. It worked and I jumped into the freelance game after a while.
But yeah, the amount of things I had going on in the original code would have been crazy if I had a puzzle with, say, 10 tiles. It was the best I could do at the time with my limited knowledge.
Regarding the mystery behaviors, this single puzzle was part of a larger game I was working on, an overhead adventure in which you had to solve a mystery and go on small fetch quests. I thought I had cleared out all the stuff that wasn't relevant to the puzzle room, but I guess I missed a few little things.