Keepy Uppy is a mini game for Hungry Shark Evolution that was released on the July 1 update. The objective of this is mini game is to score as many "keepy ups" of a football/soccerball as possible, meaning: Keep the ball in the air by as many body-bounces as you can, without letting it touch land or water. As you score more "keepy ups", you will earn more coins. It was added to the game to celebrate the FIFA World Cup. Then, it was replaced by the Death Ball for Halloween. It has since been replaced by the Beach Ball.
How to play "Keepy Uppy"
A game of Keepy Uppy can be initiated by simply swimming under the ball and hitting the ball. This will make the ball elevate. The ball must be kept in the air by hitting it as many consecutive times with your shark as you can.
Each consecutive body-bounce rewards one coin. The fifth bounce yields a gem. Realize that the only other place you can be certain to acquire gems at all times is the Crab Lair, so it may be worth it to learn how to play. The only thing working against you is - as always - your health bar. The beach ball is easy to play without the Cloaking Device and with Megalodon or bigger/better.
Strategy for "Keepy Uppy"
A Big Daddy can swim underneath the ball and elevate it with its tongue, but a Megalodon has a pointy nose, so the ball is bound to go left or right. For these reasons it is a good idea to bounce the ball low, and with the backside of your body. Usually you will not be able to sufficiently control it with high bounces. An exception might be seen in the Hammerhead or the Big Daddy, whose noses aren't pointy and who can therefore achieve a decent amount of "keepy ups" just with their heads.