Really cute game! I love the particle effects :)
I think it would have been cool if blobby changed colour and not the stage. I also think I saw some of the items were disappearing in the air at the top of the screen before falling all the way down so at times the difficulty wasn't scaled correctly. There were also long periods of time where my colour hadn't fallen at all for a long time, so maybe some dynamic probability rules could be cool there.
Otherwise, a fun little game and well done on adding a highscore too!