Simply slide your finger towards the direction you want your ball to move. The game starts with just the right amount of strength and endurance to fight against your first enemies. You'll stumble upon balls of different colors and sizes inside each level. Keep in mind that each ball has its own features. Your objective is to throw them off the platform! Hit them, crash against them, and most of all, avoid being thrown off.
At the end of each level you're rewarded with a number of coins to invest in improving your strength and endurance. This last step is key if you're planning to beat the stronger balls waiting for you in more advanced levels. Check out the top of the screen to view your current progress. That gives you an idea of the number of balls you still have to shoot down.
The best strategy is to hit your enemies hard enough to throw them off the platform. Make sure you control your movements so you're the last ball standing at the end of the level and enjoy dozens of action-packed levels.