I enjoyed evolving my build as I progressed through the game and I really enjoyed the feedback when collecting balls.
Definitely hit the 'Addictive Slot Machine' vibe for me.
I think some more complex choices would have been nice. A lot of the time I was just picking the biggest number.
Maybe if you could trade balls to re-roll a lane, or exchange balls for temporary bonuses?
Anyway, lots of fun. I enjoyed collecting all the balls :D