Answer
The answer is as follows. 
Katrielle and the Millionaires' Conspiracy walkthrough
Puzzle Location: Tower Bridge (White cat)
Stack all of the boxes to make a stairway with no gaps from the start point at the bottom-left to the top of the cliff on the right.
People can only climb steps one level at a time, and cannot climb steps of two levels or more.
Remember, there must be no gaps underneath any of the blocks.
Slide the boxes to move them, and touch them to rotate.
Place the purple L-shaped box on its side at the bottom-left.
Continuing on from hint one...
Use the orange longest box on its side on the bottom row.
Continuing on from hint two...
Place the red biggest box next to the L-shaped box.
Continuing on from hint three...
Place the remaining green oblong box vertically next to the biggest box.
The final step could be from a box up onto the top of the cliff.
The last box doesn't necessarily have to be level with the cliff top.
The answer is as follows.