EDIT: The exe has to be placed inside of the StickBall repo folder (from github) in order to work. I am going to repackage it completely.
Hey good news, there is now an EXE of StickBall.
Presto! The exe worked, so I finally got to check out the game. You seem a bit more "into" your project than most, so I'll give a more in-depth analysis and suggestions in case you want to continue working on it.
The game itself is good, I enjoyed the game play, though it didn't really feel like pong, which I guess is a good thing.
--I would recommend changing the background. It seems, with the fonts and the character sprites, that the majority of your game has a pixelated look to it. Your background should fit that, in my opinion. Some old NES or pixelated looking background like Minecraft sky/clouds would fit it a lot better. I think your "ball" and power ups could stay the way they are. The more modernized/HD look would draw attention to them in a good way.
--I can't think of the correct word or term right now, but I think the border of the game window should be impassable. Your characters can go left to the edge of the window, then appear on the right side of he window (like I said, can't think of the term I'm looking for). For this style of game, I think getting rid of that would be better.
--Your load screens don't seem to be needed. I click my shift key and it pops up to the next round. Maybe a "Press to Start Round" screen instead?
--A main menu start screen. "Start Game/Options/Instructions/Quit". Allow your character and health selections to be edited in the options, give some in-game control instructions and so forth in the instructions, and the quit game option. You do have the Esc key set to close the game, but still, a visual "Quit" option would make it obvious and look more complete, IMO.
--Lastly, maybe your character selection can have an effect on your game play? Right now, it's an unnecessary option. Perhaps the Knight's strength kicks the ball harder? The boy could be a generic or "Difficult" option. One character could move faster, that sort of thing.
That's all for now. Again, I'm not trying to nit-pick, you just seem more involved and interested in your project, so I'm going to put more interest in analyzing and criticizing it.