The idea behind this is very good and an interesting interpretation of the prompt. The execution is a little lacking. I ran into a lot of instances of the rocks bouncing me back and forth between them, which quickly became monotonous. I would also suggest a timeout of only being able to place the planks every so often, for there is no reason to not just spam F and keep the mouse just a little bit in front of the robot.
You did a great job making something so put together in such a short period of time. The robot is really cute!