Not too bad. A design improvement would be for a red bubble to simply pop the player ball. It's simple but there's no depth to explore, it just gets more frustrating and chance-dependent as it goes. So, I enjoyed the first couple levels but it didn't really hold up much past the arrival of green balls. Gold balls, I said fuck it.
So, not a bad first entry. More thought and playtesting and you'll have some good stuff in the future.