Hmm cool. I made something exactly like this before, anyway, are the angles of the ball bouncing off of certain objects random, calculated or are they just defined?
Right now it looks like ball will go from moving horizontally (diagonal) and then when the paddle hits it it just goes completely straight vertical again.
If you want the ball's bouncing to be calculated then you can change the velocity of the ball based upon where it hits on the paddle. I believe in the original pong, they had it so the ball would go farther left or right depending on how far it was on the paddle. The wall bouncing looks good though.
Also if you are going to make the ball change on where it hits the paddle, you might want to make it ADD the change to the current velocity or it will just instant change from hard right to hard left. (looks funny that way)