A flash game name 'gravity-ball'.
You can drag any balls by your mouse's clicking and holding, release the ball by your mouse's releasing.
You can also throw the ball you drag by moving your mouse.
Each ball will collide when touching others even though the ball you drag.
The ball you drag will be released when striking the wall and bound away.
Just as the name saying, there is gravity which affects all balls.
BTW, there is also resistance which decelerate all the balls.
Have fun!