thank you for playing and writing this detailed response (and finding this bug! good playtesting, me! definitely nothing would've gone wrong after rewriting the arrow tile code entirely!) definitely a thing for me to fix asap but I'm glad it apparently didn't completely ruin anything
Ah, so I thought it might have been a bug, but I didn't want to say that in case it was just me being bad at puzzles, haha. I was able to work around the bug and solve the first few puzzles where it showed up (it definitely increased the challenge, haha), but I did get stuck and had to give up on one level because of it. (I forget the level number, but I think the name was something like "Take a walk (in real life, too).") But it definitely didn't ruin my enjoyment of the game, which I thoroughly enjoyed regardless!