@Doriandoriac That's how I had it originally (before releasing Filler 1), but I thought the gameplay was too black & white (either you release the mouse and it freezes the ball or it pops). The bubble-to-bubble collisions added a "safety" element. I tend to build bubbles near other bubbles, and as the bouncy balls come my way I "retreat" to the other ball.
I submit that it's a clone of Jezzball, which is the same thing I cloned. If anything, let's say that I rekindled his passion for a really good game and got his wheels turning on how he would've done it. =]