A couple of other points:
1) You can lower the drawbridge completely so that you can go back the other way. From the beginning, go round to the side where you first got to the drawbridge, and pull the lever. After initially knocking it part way down by running at it, the lever will make it descend the rest of the way.
2) There is another way back to the start. If you go out the far side of the final 'shroom, past the dock, and along the metal catwalk you will come to a place where the catwalk is broken with a large mushroom below. Walk out near to the end of the broken catwalk and do a standing jump up in the air. The catwalk should bend down to the large mushroom and you can walk across it to the other end of the broken catwalk, which takes you back to near the solar collector thus forming a circular path around Teledahn. If the catwalk doesn't bend at first, walk closer to the edge, and jump with the caps lock key pressed.