A simple game of shooting balls from a cannon to fill moving buckets, but watch out: each bucket needs a specific number of balls to be completed and if it reaches the bottom with insufficient balls then you lose a life!
The buckets come faster and faster as time goes on, and since you have a limited number, you should use your balls carefully. Only balls that dont make it into a bucket are lost.
If youre stuck in a tricky situation you might be lucky enough to have a power-up appear. Just shoot a ball at the power-up to collect it!