At the start of the stage,quickly walk to steps left,and destroy the box underneath you on the right,to prevent the Jell from attacking you,as if you see the stage map,he is in the far right side of the ledge. After that,jump into the "hole" you just created. And destroy all those boxes in the vicinity. There are three boxes on your right,that form some sort of stair's downwards. Jump on the middle step,and facing right,destroy the box on your right(highest step.) Jump right,and you'll fall down. From than on,you will be on a wooden ledge,where a naga is below,walk right three steps,and you'll go down to a lower box. Facing left,destroy the box on your left,and create a box underneath at your left. Stand on the box you've just created,and destroy the box on your right. Wait for the naga to go to the left,and go down and grab the key. The key is below the metal block.Move one step left,and create the box,which will form some steps,and climb it up,create boxes to go up to where you first start,and win the stage.
*Note* FOR THOSE WHO WANT TO COLLECT ITEMS,follow this step,instead of passign level 20 so fast.
Stand on the metal block,which was formally above the key. Create boxes,till you reach the jell,and destroy the box which the Jell is standing on to kill it. There is a columm of metal block,stand on it. On your right,is some ledges made up of wooden crates,destroy them to get (I think so)some fireworks,and below the ledge,is a jell(so time your aiming right,and jump down when it's not there,and quickly kill it,with destroying box methdo or fireworks,you've just collected.) There is a "cox hat"(plus one life) I think,and a disc fragments. Continue back up to the starting place the door,and win.