Ranked second at Function 2015. The winner in its category is http://www.pouet.net/prod.php?which=66380. It ranks a lot lower on pouet.net, though (#6275 vs #3641)

Visually, I think pouet.net has the relative ranking right, but maybe that train is technically harder to do?

To see the animation https://www.youtube.com/watch?v=Z8Av7Sc7yGY (it's linked in the page)

The source is gorgeous too http://www.pouet.net/prod_nfo.php?which=66372