I love the concept! I feel like you might want to take a little more inspiration from Brick Breaker than Pong here with the paddle physics. Right now, when the ball hits the paddle, it just bounces off the paddle like one would expect given the angle. However, that doesn't give the player any control over where the ball goes. In Brick Breaker, to make this less frustrating given the goal of breaking the bricks, the ball bounces back at different angles depending on where on the paddle the ball hits. If the ball hits in the center, it bounces according to the angle it approaches the paddle. The further from the center the ball hits though, the more the angle will be adjusted in that direction, almost as if the paddle where a semi circle instead of a rectangle. Honestly, this one tweak would give a ton more replay value to the game.