Blow It Up 2D

The bubbles coming from the environment need to be burst. 
Increase the number of balls coming from the pipe and pop the bubbles. 
Upgrade and improve balls with the money earned for each bursting bubble.
Increase the number of balls and try to pass the levels quickly.
The more balls there are, the faster the bubbles pop.
Don't forget to merge 3 balls to get a top level ball.