Spend coins to upgrade Frankie, your starting character because it will be awhile before you can unlock an additional character. You can improve his Speed, Energy, Turning, and Magnet. Speed allows Frankie to fly faster. Energy increases his available energy. Turning allows his movements to be sharper. Magnet affects the magnet power-up. Focus on Energy and Speed at first, followed by Turning. Because the Magnet is situational, you can upgrade that last.