Good level! Yes, easy, but I thought B might be stuck after pushing the last ball. Spoiler But you'd left a nice corner space for him to pass P and reach the star.
I think I found the shortcut too. Had to play again, the design is so cool. Spoiler: Shortcut Run 2 or 3 blocks towards the star, then back in a loop, and B can touch the star!
@Lipled Top Ball sometimes stuck inside the tunnel. Even half moved, where it is supposed to be stop / halt. Logic and moves are nice. Need to work on stability and cheat-proof approach.
Spoiler: Shortcut If you go quick, you can do the way back after push the last ball, getting upon it and going to the side of the star to step on L. Now it worked!