The game is enjoyable. The art assets were good, but maybe a little unrelated. The sound was good and the music was great as well.
For the gameplay, I liked the idea, but i feel like the game is currently very luck based. I got to about level 8 (Stable Environment) without doing anything except just going into a corner and hoping that the physics helps me get to all the infected balls, there is no real strategy needed.
I think it would be better to try to make it more like a puzzle game. Maybe if you were only controlling the blue ball and the other balls moving with just their momentum, or maybe different, more difficult maps in the higher difficulties instead of just adding more balls.
I didn't find many bugs in the game, just a couple. When you fail a level and retry it, you start with 2-3 more seconds than last time (don't know if this is a bug or intended). Sometimes when the balls hit each other fast enough in a corner one of them will go up and be on top of the other balls. In unstable environment, sometimes one of the map corners rotates out of camera view.
All in all, a fun game idea that just needed more development time. Good luck in the jam.