Planetertainment

B does move and B did it without the ball.

Spoiler

The movie method is easier. Thanks

I had to watch the movie just to make sure I was doing it right, and I was, but apparently the angle also matters for that push...
Easier than expected after that! Funny that I was using autopilot...
Plain entertaining level. Good thing it's intuitive, the solution won't fly over most player's heads, hopefully most users high expectations will be met . Thanks!

@gmacpro

Spoiler: some shortcuts

You can win by only squeezing the movable with the fence. And you can use the magneto trick or the ascending free slider to get up without the ball. The latter was a side-effect of a last-minute change for esthetics, but the others are, I think, not intuitive. But good finds!

Very funny, good puzzle in such small space. Thanks!

Excellent puzzle!! Really enjoyable!! Thanks and well done @Block builder