That TAS is spliced. The stairs beyond the door aren't loaded, you need the key to load it.
This is a real console 0-star TAS: https://youtu.be/iUt840BUOYA
if let makes a lot more sense when you learn that a normal let expression also takes a pattern[1].
let Coordinates(x, y) = get_coords();
But this is intended for "exhaustive patterns". If you can't express an exhaustive pattern, like with an Option, then you can use let ... else let Some((x, y)) = get_coords() else { return };
if let is just an extension of this "let pattern" system.Once you internalize how patterns work (and they really work everywhere) it all starts to really make sense and feels a lot cleaner.