apparently pushing the stone backwards is also viable, was kinda forced to do it every time i got the stone up to the top
since this was made in godot i will suggest that you should try to use Area2D nodes to detect if the stone (which i assume is a RigidBody2D node) enters an area (like the top of the hill) using a body_entered signal rather than using the eternal void
to be honest though the concept of a boulder-rolling factory is amusing and it would be nice if it could be fleshed out one day