Great job
But Pong has been done to death. Do a search for 'Pong' on Newgrounds and I'm sure you'll get like 10,000 hits. If you want your game to stand out you need to make it original. As a fellow game developer I understand how hard it is to make fun, original games. And making clones of previous games is a great way to start off but if you want to start getting them up there in the scores you'll need to eventually make your own game. As far as improving this one you can add music from the audio portal, maybe add another ball, a background, but I'm pretty sure no matter what you do it will always be scrutinized for having 'Pong' in the title. Good luck on future games and have fun =)