From a start door, go toward the left and you'll find three ladders.
Climb the first ladder from the right.
After you got to the upper floor, move to the right.
An appearing wooden box will fall down.
Go up to the upper right brick floor by using a fallen box.
Swallow a wooden box on your way and move to the right with keeping swallowing.
Then release it under the upper right floor to go up and climb a ladder in front of you.
After climbed, go toward the left.
There is a wooden box near a door.
Swallow it and go forward to the left beyond a ladder.
Then go down to the lower floor with keeping swallowing.
An appearing box will fall.
Release a box there and make steps with two wooden boxes in order to get a key.
After got a key, turn back your way and go pass a door.
You can find a ladder on the right of a door, then climb it.
When you get to the top of a ladder, two appearing boxes will fall.
Arrange them to go up to the upper left floor.
There is a wooden box on that floor.
Bring it to the lower left floor and climb a ladder on your left.
After climbed, go up to the upper left floor by using a fallen wooden box from your left side.
Then go toward the left.
When you come to the end of the floor, go down to the lower floor.
There are three piled boxes.
The bottom iron box is breakable so let's break them.
Go to the right further and break piled boxes again.
Lastly fall down from here.
There is a goal door on the bottom.