Level 72 on 100 floors is a race track stage of a sort, well it looks like one anyways. When you begin the stage, you will see that in 100 floors, stage 72 that there are two checkered flags on the top right and top left and a checker line at the top. You can actually use the knife to cut the flag on the right to reveal a < mark to help you in solving the puzzle.
Once you are done examining the stage, it’s time to solve the puzzle. In short, we will just let you know how to solve the puzzle, make sure you are on a fresh start of floor 72, once the stage begins slide the yellow to the top then slide the red. Once the red and yellow is at the top slide the blue then finally slide the green. This will unlock the door on floor 72 of 100 floors.