A good variant of Pong, nice work so far. There's just one thing, I don't really like and it's this - whenever the player or the CPU-player scores a point, a new ball suddenly shoots in, from the center-line immediately afterward and sometimes it's nearly impossible to catch this ball. It would be better if, after a point is scored, the ball always originated from the backline-side of that player, whose backline it had just crossed (i.e. the player who didn't just score).
That way, you would always have enough time to catch this first ball. At the moment, the ball comes flying in, from the center-line rather than the backline and sometimes the reaction window is too short, to respond quickly enough. Otherwise, I like the game. Support for real paddle-controllers would also be a cool addition, by the way. At the moment, it looks like only joysticks/gamepads are supported.