Yeah, adding gravity seems like an overall good idea. Otherwise I guess the ball would feel very "stiff". I mainly noticed it during level 3, so it might be possible to prevent the problem altogether with a small change in level design, yes. There is that small gap you have to navigate the ball through, surrounded with sticky green zones on the top and bottom. If you aim exactly for the gap, the ball will always get stuck. So in order to finish the level, you have to to aim quite a b it higher. Not a big issue, but it felt a bit counterintuitive still.