Coins can be obtained in many ways. One of the most common is during a Run. There is a Power-up, the Midas touch, which will turn all the Enemies into Gold and help you get extra Coins for a limited amount of time. Apart from that you can loot them by breaking obstacles during the Run and collecting bags full of Coins. It doesn’t end here, you have the Portal Quests waiting, let them surprise you.
The easiest way of getting Coins is by making in-app purchases from the Store. First you have to buy the Essence which you can later on exchange for Coins.
There is also the Free Chest opening which rewards you often with Coins.