Hey! Thanks a lot for playing! A big chunk of it was using this method from the Label (Label — Godot Engine (stable) documentation in English), which gives a bounding rectangle and then just checking against the user drawing haha :)
And on the final call replay bug: it was definitely not intentional LOL. I tried to make a saving system work (which I ended up having to leave out of the game), so that's probably some dead code there messing it up! Thanks for the bug report, btw!