it's good for a first
it's a good first game. I would suggest having the balls of higher point values fall faster than those with lower point values, and having a way of losing points either by catching things that lower your score or by having a penalty for missing certain balls.
I would worry more about game mechanics than the visual audio stuff, at the moment. Just keep tweaking it and adding things, and once you get the game to play how you want it to play, then work on that aesthetic stuff, and resubmit it.
If you want me to help you out with some of it, I would be more than happy to collab with you. Anyways, can't wait to see you crank out some more stuff ^^