I was more surprised by how effortlessly the guy sped through the Bowser levels. Even with it being tool-assisted, it's amazing that it's possible to get through the worlds that fast. My favorite part was the jumping along the fringe of the lava pool to get to the other side. I always knew you could somehow use that narrow platform.
I'd like to see a similar tool-assisted thing for speeding to the top of Tick Tock Clock.