The art style was simple but great and I liked the overall idea. Got very hard though! I couldn't manage the level with reds and blues each having the three rock stack. Makes me think I might have missed some trick to the game.

I recorded myself playing, the video is here if you want to see:
https://www.youtube.com/watch?v=9yGg3lucYHM&index=17&list=PLdLeOxRHtRXoFhBNnWybP1VhJ6jYGiIO5

Love your art style, and the game concept is fun. I don't think I was very good at it, though. Got fairly stuck on the second screen, but did the third in a flash! A very cool blob, indeed!