Nice game! This has some interesting mechanics to it. A few suggestions:
* Needs some kind of visual response when you lose health, since there's a distinction between your core and your jelly. Screen shake, flashing the screen red, or something like that would help.
* The first time I played, I appeared in a room in the upper right corner that had no exits. It looks like the level generator tried to create a corridor going south out of the room, because it had two columns of "#" characters leading away from it, but there was no space between them to move my jelly down.
* Cosmetically, it might be fun to let you choose the color of your jelly. And some squishing noises as you move might be satisfying, too.