Really interesting mechanics. Now for a couple complaints:
1) The difficulty jump from tutorial 3 to the trial was WAY too big. I had to quit at the last checkpoint because it was too hard.
2) The music stopped looping at one point :(
Other than that though, I had a lot of fun with this game. I really like how you can control the amount of force you put on the balloon, it makes what could have been a really annoying and hard to control mechanic into a great one. When the music was there, it fit pretty well, and I liked the art. The overall aesthetic combined with the gameplay reminded me of something that would be on cool math games, and I don't mean that in a bad way. Great job!