Coins are an in-game currency. You can use them to buy Boosters and Power-ups in the game. At the end of the level, you can buy for coins extra turns as well!

You can get coins:
• from the daily login bonus (it's free!)
• when you beat a level on the first try
• by exchanging character kits in the tinker table
• by purchasing them in the shop
• by watching an ad in the shop