So I just got out of the starting area, and I found the abyss for the first time - she mentions something about needing a light source before I can go in there. Soon, I find a couple of glowing fish that follow me when I sing - so I make my way into the dark. I lose one to a big jelly thing, but the other one makes it through with me all the way down to the glowing plant seed treasure, and finally to the save point in the glowing centipede room. However, the fish dies on the way back - and when I reload my save, the fish isn't there. Further, I can't seem to pull the centipedes out of the cavern to light my way back - I give up, how am I supposed to find my way back through the darkness?
edit - oh crap, am I screwed? reading through the other posts a bit, I gather you get some sort of ability to light up the dark areas - did I just find a glitch that lets you skip that, but without any way of getting back?