You have the option to reset your game in the setting (open the menu by clicking on your level )
But beware : If you reset your game, only the SkyCoins (gold coins) bought in the shop are refunded.
It means you lose: - Airline tokens - Construct tokens - Event tokens (tokens available during an event) - Dollars (Soft Currency) - Sky Coins you earned with the game (missions, level-up, Airline Passes, perfect contracts, etc...)