You can equip power-ups before each game. They cost some coins every time you equip them. As long as you have enough coins, you can equip up to three power-ups in each game.
Power-ups you equip will appear onscreen as you play the game. Just touch them with your goats to start using their power. Their effects will last for a limited time.
*If you decide you don't want a certain power up, just tap on the item in the power up menu bar.*