I like that you kept the simple artstyle for Pong - it is tempting to add all sorts of bells and whistles for an extremely simple premise.
The paddles didn't shrink on scoring, which would have been an interesting balancing mechanic for the game. Would the shrinkage be related to how many points have been scored by the player (i.e. the paddle shrinks in proportion to the score) or the difference between the player's scores (i.e. the leading player's paddle shrinks, and eventually regains its normal size as the score difference decreases)? The movement and responsiveness of the paddles was fine.
I think a possible improvement would be to have the ball remain stationary in the center until the spacebar is pressed, as the ball does travel fairly fast. Another is some extra text to let the player(s) know that pressing the spacebar after the game has ended restarts it.
Overall, it's a simple and basic game that has the added bonus of allowing local multiplayer.
A straightforward game of Pong.