Spoiler: Top Ball To get R to turn to that top ball, B needs to be standing on something to reach that wedge. That doesn't quite give everything away. And yes, I know that's a really unintuitive setup for a certain trick. I personally think it's kind of cool though, although it does make this probably one of my five sneakiest levels.
Phew! Solved it. I couldn't have done it without the hint. That exploit is really not intuitive at all, but I now know it. Looking forward to the next puzzle. For my money "Pacific Bunker" remains the best puzzle you have made and the best of ALL contributed puzzles.
Saw a reference to this level today and I must have missed it when first posted. Liked the level though i won without using the secret passage.
@RZK thank you very much for your VSs of Star Penguins levels. A good way to learn. In this one here, there are two draggables you did not use; i dont think it's penguinlike.