I gave your level a go and it was more like Faller than Jumper. I had no problem getting B to the windmills however your two rotors that lead to the windmills are not very smooth as the motors are hitting the stone block. You should make your rotors smooth. I attempted to get thru the windmills and few times and B didn't make it. Since you didn't provided a recovery for B if the windmills knock B off - I had no plans to redo the entire level over and over to accomplish the last part.