Exit with Puzzle: The Deserted Lighthouse

You trudge along the dark, rocky coast seeking shelter from the raging storm. A lighthouse suddenly appears and then, inexplicably the light goes out.  You glance out to the water and spot a ship sailing straight towards the cliffs.  It is up to you to race to the top and turn the light back on again, before the ship crashes on the cliffs. But many puzzling obstacles stand in your way.