At the start of the stage,while facing right,jump and destroy the box on your right,and move one step right,the blue monster thing,will get out of it. Once it get's out,jump inside,to the right,maximum and jump up to get the golden key. At the place,where you destroy the first box,create a box in it's place,and destroy the box on top of it,and stand on the box,of the box which was just destroyed. Facing left,create a box,and jump on it to grab the the big bomb. Go left one step,and facing right,jump and create a box to seal the first blue monster,by that time has gone on top,and will be "sealed" there. Facing left,jump and destroy the two boxes next to each other on the left,and the next blue monster will go to the leftenmost gap,seal it up and quickly enter the door,and you've won this stage.