Heck, played the latest version of Momentum at the time of me writing this comment (the one that introduces options (thanks!)) and I noticed that when the scaling setting is changed, the ball becomes invisible during gameplay and stays invisible upon pressing R to reset for a new round. :o The ball's visible again upon closing and reopening the game though. (Also the volume & scaling reverts back to 100% and 3x respectively when you close and reopen the game.)