Reaction

@delator77 you didn't use any of the sliders on the other side. Is B meant to use them to step up somehow? It's all very mysterious.

I tried again and B fell off. From there I was able to walk round and use the sliders to reach the top! But when I got the star B was stuck on the pipe. (Why couldn't he walk back like in @delator77 's video? )

I find the shortcut @delator77 uses too tricky for me, B always falls down onto the zapper.

@Chris Hester You can read my spoiler in first comment, I gave a little hint there. It might help you, but if not, then here's a...

Spoiler: big hint

Using the lower slider, all you need is one simple quick slide to the left and start from there.

@Logo SHEEESH SANAOL NAKAKAIPON

@delator77 @Chris Hester

Spoiler: Correct VS

@Logo By the way, there is another problem at this level that I forgot to mention, but when I was recording the video, I remembered about it:
0:09 ...The slider that pushes the free element often gets stuck! Since timing is needed at this point, B often dies due to getting stuck and you have to restart the level. Because I try but don't have time to click on the slider that is stuck.

@Denis Nazin

Almost the same gameplay as mine. The difference would be how to

Spoiler

squeeze B all they way up. I pushed and squeezed B in different position and direction of the draggables

@Denis Nazin Thanks for the video!
About the slider getting stuck, I did encounter that but adjusting/rotating the viewing angle fixes it. Yeah it's weird physics. I could've made it more stable.

Also, there is a cleaner and more steady way to climb those compression stairs.