If you fall enough that if you were to suddenly land it would kill you, if you use the air smash(B in mid-air with walking stick or Sting) you will appear to have landed very painfully on something supported by Bilbo thoughtfully remarking "OH!...Unhhhh..."
If you fall for a very long amount of time(Most easily done in Smaug's lair, after Smaug has left, from the top into the chasm) then Bilbo may teleport back to the nearest flat ground from which you jumped.(Likely done by the programmers to prevent being glitched and stuck.)
Once you have found all the children and given all the food to the dwarf bombur. You may go back to the apple orchard. Look for a well that used to have a man standing next to it and go up to it. Hit "b" and and waters of vigour potion (used to make your life bubbles purple and prevent damage for a short time) will be acquired.
Defeating Smaug: The Ring will be no help you have to stay behind debris until all of the fires are gone. If you take one step out you will die even though it appears he has stopped there is still fire there.
Saving Beorn: Push four different blue barrels located around the area in order to save Beorn on the last level.
Follow the Courage Crystals without stopping to fight and use the ring when you encounter enemies to advance quickly as you are being timed.
Wine bottle riddle in Lake Town: Get all 5 wine bottles in Lake Town and Malloc will tell you a riddle about how the bottles are arranged. The following is the order:
1. Yellow Wine Bottle 2. Blue Wine Bottle 3. Red Wine Bottle 4. Black Wine Bottle 5. Purple Wine Bottle