This is a cute little game, for me it was a little frustrating though haha. I've not played any ball rolling platformers before, so it's hard to say - but yes, it's very difficult to stop rolling. Also, in the levels where depth matters (i.e., the circle pits in the last 2 levels) it is very hard to see where the actual incline begins, I think maybe it's because the ground is dark colors in those stages (black and dark green).
Also, I did not realize it wasn't necessary to get all the seeds until I beat the game and saw a seed counter for each level, whoops
Anyway yeah, this is a really cool submission and something to be proud of as your first ever game jam game. Awesome job!