Mario starts off on the bottom non-moving platform. He must ride on the Conveyor Belt that is moving left and crouch under the wall in his way, then go left and climb up some ladders past some fake doors. Once at the top, Mario must jump up to platform with the key, grab it, then head right and throw the key onto the Conveyor Belt moving left, which goes through a small hole Mario cannot enter due to a spike blocking the way, then he must wait until the key falls onto the second Conveyor Belt, at which point he must pull the switch to change the direction of the second and third Conveyor Belts. Mario must then climb down the half ladder down to where the next lever is, where a ladder block can be found and used to connect to the half ladder just in case he has to start over. Mario must grab the key to prevent it from going back to where it was, then throw it onto the third Conveyor Belt and pull the lever before going down another ladder to another lever. Mario must then pull the lever to change the last two Conveyor Belts, grab the key to reset the key's timer, activate the ladder block and place it out of the way of the lever, then pull the lever back and place the key on the Conveyor Belt while avoiding a cannon's shots. Mario then must climb down the ladder and pull the lever once the key is on it so he can grab it again, then throw it onto the Conveyor Belt and pull the lever so it goes to the left. Mario must crouch to pass under the wall to follow the key. Once past the wall, Mario must grab the key then jump and throw it up to some platforms with some fake doors; the real door is the third one in the row of doors. Mario must throw the key up to the real door to end the level.
Pauline's lost items
Within this stage, Pauline's lost items can be found in the following order and in the following places: