Hi and welcome to the forum. Maybe there's something hidden, but after all the waiting around, I ran out of patience and used an inertia trick that I'm pretty sure you didn't intend to help B reach the top.
Welcome to the forum. The level was boring as the auto sliders have that effect. When B got to the top, my first thought was "Are tricks required?" Short of doing a Boogie Bot in the corner, I can't see how B will get up. Can you provide a video of the intended way?
Patience is not enough to get B to the win. The final step is pretty tricky. The rest of the journey is quite boring.
@gmacpro Spoiler: Final step When B is on the red-brick ledge just below the win, I made run B back and forth around the (safe) corner. At a certain point, B legs grow longer and then I tapped on the higher level. If you are lucky, B climbs up and the rest is simple. If you are unlucky, B runs into R and gets zapped.
@GFJ - Thanks for the hint. You did it as I wondered but the lower part is so simple that I figured the author intended something else. Doing the Boogie Bot up is much harder than going down so I really hope the author has another way. @JAYVERLY08 - Please advise on intended method for final move.
@JAYVERLY08 - Bump - please answer my question... How was B to get to the win, the last move up the stairs?