I got all the upgrades! It was a little bit addicting near the end. I enjoyed that increased speed allowed for new tactics of sweeping upwards to swipe past the ball. Good fun.
Small thing to consider: With such a strong focus on maintaining streaks, adjusting the player slope to allow to better redirect balls going backwards would be very nice! The front of the rectangle is low and points down -> expect to be able to rush towards the ball to bounce forwards but it doesn't work. Creates a behaviour where balls just have to be given up on.
2nd small thing: Consider graphical change for balls that have gone through the hoop. In the chaos, sometimes I rushed to get a ball into the hoop only to get no points because it had scored already! Perhaps a timer on the balls that allow players to rescore on the balls after a set period of time?