Almost threw in the towel!
Ran into some code related problems. The main idea with this game is to eat smaller jellyfish in order to grow. To do this I had to resize both graphics and physics, and I did not prepare my code for it! Solved it by creating new objects where the old ones used to be. Not perfect, but it works!
Here comes a video of a tiny jellyfish:
And one with a large jellyfish absorbing a smaller one: