This was a neat take on pong. It took a bit of experimenting with the different abilities to get a feel for them, but they played well. I made it to level 5, before I started to mess up a lot. I'll probably try again later after some sleep.
The UI could use some work. At the default size, the font size of most buttons is too small and hard to read. The game over button I could not read at all. The buttons themselves are plenty big enough for a much larger font size. On the controls screen the blue of the background feels a bit bright for the white text, and I'd suggest making it a bit darker to increase contrast. The font there is better, though bumping it up a size or two, if everything still fits, would be nice. Adding a Margin Container around things to move the text off the left edge would also look better. It doesn't have to be much, even 4 px might be enough.
I like the addition of the checkpoints, though personally would prefer being able to restart on each level. Perhaps you could add a "difficulty" setting for how often to have checkpoints.
It felt like later levels required more points to win. It would be nice if the level start screen said how many are required to advance.