I remember in Construct Classic I used a fantastic shader effect which would detect the edge of sprites in a layer and 'ignore' the fill of everything, it gave me this quite cool effect:
youtube.com/watch
I'm wondering if it's possible to reproduce this effect with C2's new WebGL effects?
Also there was that Blobber, liquid 2D simulation effect made in CC which I used and worked fantastically. That also had a shader processing effect to blend the blobs of liquid together, I forget what the process was though...