This is extremely hard. I thought there were only two very difficult problems(making a high ball fall and stop to act as a bridge: making a R cross over and turn left to knock the ball nearest the winblock) , but having solved them i still cannot win. If only the fence draggable could completely freeze pillarbot then i would be able to win .
Returned to this level and finally won. I had made a basic presumption that was wrong. Spoiler: Mistake I thought that if an R pushed on of the two high balls (on the metal half pillar) then there was no way to get him back. Because of that i was trying to push the high ball with B that meant i could not stop pillarbot from moving so that could not form and keep the bridge. The breakthrough seeing how to get R back was not an easy move and took about five attempts to get right. Nice finish seeing that the three rbots were required as anticipated.
@乌鸦嘴 .I saw the video in the link. It shows R releasing the ball near winblock same method as i used. I cannot upload to your site but have uploaded video of crucial move in the spoiler. Spoiler: Crucial B move
