This is...well yea, boring
So, I like the idea of getting extra points from popping the same colored balloons and then adding a slew of other balloons to try and fell you.
Some things that really hurt the game:
-It's painfully slow. If you doubled or tripled the speed he flew at, it'd be more challenging
-No sound. There's just not enough other stuff to justify a lack of sound.
What I would suggest:
-Speed it up
-Add music first, and then sounds after the music is in
-Add another mechanic or two. Maybe an updraft mechanic that pushes you higher than you wanted to be.
-Make the the character and his hang glider smalled. They take up a lot of room as is.