Very cute! I thought you did a really good job of scaling up the difficulty as the game progressed. I had the most fun when I was moving without stopping and had a lot of momentum, making all the bubble sounds and flowing through the level.
I got a little frustrated during the first electric fence level at the part with the three little bubbles all next to each other and the fence above them. I felt like sometimes I could just go bubble to bubble without any upward trajectory, and other times I would just fall down.