Review (1/5): More 'Wobble' than 'Roll'
Added the battery and started it up, set on the floor. The sound of the ball kind of frightened my dog initially. However, it began to roll, then stopped in place and merely 'wobbled' back and forth until I intervened and nudged it again. It rolled for about a foot then started the wobble again; my dog completely lost interest. Seems like the mechanism is 'underpowered' to keep it moving, but I swapped out batteries to confirm it wasn't merely low voltage causing this wobble effect.
Overall my dog never got interested in it due to the factors above. Great idea, just didn't work.