Well ... to me it seems like the ball loses quite a lot of objects when it makes contact with something big. I mostly noticed in Stage 2, since it seems you have to pick up nearly everything in order to grow big enough to leave the first section of town and gain access to most of the rest of town. (You probably don't need to roll up almost everything but that's how it felt.) Since the ball loses a lot with contact, it feels like you have to be very careful or else you may never reach 3m or whatever the barrier required. So in my opinion Stage 2 was a rather hard stage, over a month ago when I played it.
One of the Meter Meyhem areas made my PC slow way down; you can see in my third video. "Meyhem" may be misspelled but that's okay with me.
Otherwise I think the game's really great so far. I loved the whole town setting of Stage 2 (I thought it was a great stage even though it's hard), and all the short Meter Meyhem contests are a great idea (and the rollable lobby is an awesome touch). I am not good at thinking of suggestions but if anything comes to mind I'll be sure to post.
And of course I'll be hoping for even more stages. :)