This is a fun little game. I didn't try if it has controller support, but mouse support could be handy. I find that I am too slow on the keyboard and being able to quickly move the paddle with the mouse would make it much more fun.
I like that there are so many modes. On one hand it's cool. On the other, it's overwhelming. I don't have any good suggestions on how to streamline it though. Just glad that you're trying out new concepts. My own logo is a remix of images from openclipart.org. There's no doubt you can find something there that can help.
I think your icon and logo looks like AI even though the game itself probably doesn't use AI for anything. It may be worth just making your own, even if it is simple.
What do you think about making a 4 player version? I had this idea for a while now, and there could be two variations. One variation is where there are two players on each side.
The other variation is that there are 4 scoring areas instead of just 2, with each player defending theirs.
Could be an incredibly novel way of approaching pong multiplayer.
A bonus could be network multiplayer on top of that, but if you had 4 player support on the same computer, then Parsec could easily fill that gap (or Steam Remote Play if you ever release it there).