As long as it satisfy this rule: "he can only climb up or down one box at a time."

how to understand the instruction "Block dude can jump over a box on the top layer"?

1. The block dude can jump over one box on the top layer.
2. The block dude can jump over several boxes on the top layer.
3. The block dude can pass through the top layer if it is filled with boxes from the current position to the end.

fantastic! a real Goldberg machine!