Really nice. I would add an animating affine transform for the goo blobs so when they approach the top they get narrower and longer. This way the individual blobs would constantly change shape too making it a little bit more "gooey".
There are lots of things I would add to this (and your suggestion is one of them) but I wanted it to run on mobile too - therefore I had to 'feature-cut' where I thought it would have the least visual impact.