Thank you very much!
We initially had plans to make the line change color when it's too steep, but since we're working with unity phsyics we don't actually know what slopes the chicken can climb and which it can't. If we had more time, we would have tried though.
After coming up with this idea, we actually thought of the witness, but we went for it anyways. In the end, it was hard to judge the difficulty of the levels and the order is a bit random now, true.