The hitbox properties feel unjustified, so much so that I sometimes feel like I hit the back of a ball and it still cheesed me to its front, making me die. I also cannot gauge how much I'm going to be taken back by a ball and how much pressing I need to do to do the biggest hit - if at all. Furthermore, I have NO idea how the black balls work, sometimes I hit them and they die, sometimes they don't die, what?!
Also, it might be a neat little reference to Pool, but for laymen, we have no idea how many lives we have.
Those are all nitpicks, mind you, but I KNOW it will really help you to get more detailed feedback like this. sorry I didn't do this earlier!