This an expensive pay to play game. You can't progress without buying flip coins with real money. It requires you to use them to finish jobs and progress gameplay. However, it is not possible to earn enough through achievements and leveling to progress through the game once you get to around level 15. It's designed to hook you with the great mechanics and game play and constantly adding new items to purchase so once you get to that point you'll start shelling out the big bucks.