Very creative concept! I really like the chromatic aesthetic to the loop. It is definitely a challenge to get the hang of, to get a feel for the "weight" of the ball and the strength of the throws, but I think the balance of encouraging stacking as many gathers as possible was smart. Also, it was clever to destroy the boxes if I draw a loop around them :>
One thing you might change is: clicking anywhere, not even on the ball, loses a life :(
Also, for some reason, the first load played at an extremely low framerate for me. I had to reload the page, and then it played normally :o