A bit of feedback:
-It would be nice if it was easier to see which buckets are close to upgrade, as is you often have to wait until the background lines up to make it visible
-The auto drop scaling is really bad, making it a practically worthless upgrade, as the auto drop is so much slower. Having it make more of a difference, maybe aiming for about a third or a half of regular clicking, would be nice.
-It would be neat earlier levels were still relevant after unlocking the next world. Maybe something where the average income with autodrop is calculated, and the money earned can be used for bonus balls or powerups in the current world.
Otherwise, great game!