That sure was a nice game.
But it took me ages to figure out what was up with the disappering and appearing stuff, thought of a glitch at first. :-D
Thanks! Yeah, I thought it would be kinda obvious like the boos are in mario but since it is based on rolling direction and physics, it can be way more confusing and harder to figure out. If it wasn't a jam game, I would have most likely caught it with some playtesting and then added in a better introductory part for it.