Too unstable for me. The ramp climb at the beginning isn't guaranteed to work - B might get stuck up there. The ball inside the tower - once you've gotten it in place, it's very hard to tap it because of the limited space visible. And the final move... Spoiler B would not stay stable on R, no matter how carefully and slowly I moved the draggables, so after a couple of attempts I gave up. The cleanness of the design is marred by those two fences sticking out - a wedge in the landing zone would be better, but otherwise the two towers look is good.
