I was talking about the change you suggested me to do with the console.No, it wasn't a bug, it's just that I want to challenge you players a bit! When MC shows Valerie the toys for the first time, Valerie mentions that this plug is a challenge for which she must be prepared.
Maybe I will build another little hint if someone has only the stone plug left.
Regarding the minigame, I think it's a good idea. Because it wasn't obvious which was the solution to unlock the the last option, after having tried different options.