Story-related so not missable.
You need to put yourself together...
Click on your body.
Click on your head.
Now you need a leg....click on the doll, and give it to the animal thing. He/she will give you a leg.
Click on the magnet and click on the spool to get string.
Put them together in the inventory at the top.
Walk over to the edge, and push over the pole.
Use your magnet-string on the pushed over pole to get your other arm and swing across.